Retrospective Post-Market Clinical Follow-Up Study of GORE-TEX® Vascular Grafts and GORE® PROPATEN® Vascular Graft in Peripheral Artery Disease, Aortic Aneurysms, and Dialysis Access: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Retrospective Post-Market Clinical Follow-Up Study of GORE-TEX® Vascular Grafts and GORE® PROPATEN® Vascular Graft in Peripheral Artery Disease, Aortic Aneurysms, and Dialysis Access (NCT05124184), a registered phase not stated study. The primary outcome is PAD Cohort: Primary Safety Outcome: Device-related Seroma or Infection.

2. Clinical Question

3. Trial Design

This study is a multicenter, single-arm retrospective registry based on chart review. Its stated purpose is to confirm clinical performance and safety of GORE-TEX® Vascular Grafts and GORE® PROPATEN® Vascular Graft throughout the device functional lifetime for each indication area. The registry record lists PAD, AAA, and end-stage renal disease among its conditions and gives enrollment as 356. The study status is completed; the listed start date is 2022-01-24 and the primary completion date is 2024-07-22.

The three cohorts reflect different clinical settings. The PAD cohort concerns bypass for peripheral arterial disease or peripheral arterial aneurysm. The AAA cohort concerns open surgical AAA or thoracoabdominal aortic aneurysm repair, performed simultaneously or in stages. The dialysis access cohort concerns graft creation for hemodialysis in people with end-stage renal disease. Device options named in the cohort descriptions include GORE-TEX® Vascular Graft, GORE® INTERING® Vascular Graft, GORE-TEX® Stretch Vascular Graft, and, in the PAD and dialysis access descriptions, GORE® PROPATEN® Vascular Graft.

Because the study is retrospective and single-arm, it describes outcomes observed in registry records rather than outcomes under randomized treatment assignment. The record does not describe a concurrent control group, and allocation is not stated. The cohorts therefore should not be interpreted as comparative arms: their indications, procedures, and follow-up contexts differ. A direct treatment-effect contrast is not established by the design information reported.

The primary endpoint is specific to the PAD cohort and concerns device-related seroma or infection. The registry also lists secondary outcomes covering limb salvage, amputation-free survival, adverse events, patency, and infection requiring reoperation in specified cohorts and timeframes. Although 13 outcome measures are recorded, the registry record reports no analysis entries. Detailed cohort characteristics, the timing and completeness of individual follow-up, and the statistical analysis plan 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 PAD Cohort: Primary Safety Outcome: Device-related Seroma or Infection, measured over Data were collected retrospectively from health registries, for up to 5 years after index procedure date.

The primary endpoint is the percentage of participants in the PAD cohort with device-related seroma or infection. The endpoint definition covers clinical evidence of an infectious process in the direct vicinity of the access site or distal to the treated vascular site, as well as seroma that the registry investigator classifies as primarily related to the registry device. The stated timeframe is retrospective data collection for up to 5 years after the index procedure date.

In general, a safety endpoint aims to capture an outcome that may reflect an unwanted event associated with a device or procedure. Defining the event and the relationship to the device is important because the same clinical event can have different causes. In this registry, the definition combines a clinical description of infection with an investigator judgment about whether a seroma is primarily device-related. That makes the classification dependent in part on information in the chart and the investigator’s attribution.

Reporting the endpoint as a percentage of participants expresses how frequently the defined outcome was recorded in the relevant cohort. A 95% confidence interval, the stated dispersion measure, would describe the statistical uncertainty around that estimate. The registry record does not report the observed endpoint percentage or its confidence interval, so the magnitude and precision of the primary safety result cannot be assessed from the reported information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The statistical information in the registry record is limited. The study is described as a multicenter, single-arm retrospective registry based on chart review, and the primary outcome is a percentage of participants with a 95% confidence interval. No analysis entries are reported. The detailed statistical plan, endpoint estimation method, and rules for incomplete observations are not reported in the registry record. The concepts below are general explanations of how such methods are commonly interpreted, not claims about methods used in this study.

What does a percentage endpoint represent?

In general, a percentage endpoint expresses the number of participants meeting an outcome definition relative to the relevant participant denominator. It is important to know which participants are included in that denominator, how event status is determined, and what follow-up period applies. For a retrospective endpoint with follow-up extending up to 5 years, differences in the amount of available follow-up can affect how often events are captured. The registry record does not report enough detail to establish the denominator or follow-up completeness used for the primary endpoint result, and it does not report that result.

What does a 95% confidence interval convey?

In general, a confidence interval describes uncertainty around an estimated quantity under a statistical method and its assumptions. It does not describe the range of individual participant outcomes, and it does not prove that an underlying value has a particular probability of lying within the interval. The width of an interval depends on features such as the amount of information available and the variability of the outcome. Here, the registry identifies a 95% confidence interval as the endpoint’s dispersion measure, but the interval itself is not reported in the registry record. Its precision therefore cannot be evaluated.

Why does the single-arm design matter?

In general, a randomized comparison can support an estimate of differences between assigned groups when its design and conduct justify that interpretation. A single-arm registry instead describes outcomes in the patients whose records are included. Without a comparable control group, observed events cannot be contrasted to determine what would have happened under another treatment or without the device. Retrospective records may also reflect clinical decisions, documentation practices, and follow-up patterns that were not controlled by random assignment. These are general considerations for interpreting this design; specific bias assessments are not reported in the registry record.

The three cohorts should be interpreted separately because they represent different conditions and procedures. PAD involves bypass for peripheral arterial disease or peripheral arterial aneurysm; AAA involves open surgical aneurysm repair; dialysis access involves graft creation for hemodialysis. A numerical difference between cohorts, even if one were reported, would not automatically represent a device effect. Differences could reflect the underlying clinical setting, patient selection, outcome definition, or observation period. The registry record does not report a comparative statistical analysis across these cohorts.

How should retrospective follow-up be understood?

In general, retrospective follow-up depends on information already present in clinical records or registries. The amount of time with available records can vary, and missing or incomplete documentation may make an event difficult to classify. Time-to-event methods can account for differing follow-up under specified assumptions, whereas a simple percentage may depend strongly on the denominator and observation window. The primary endpoint is expressed as a percentage, and its timeframe is described as data collected for up to 5 years after the index procedure. The record does not report whether the endpoint was analyzed as a simple proportion or with a time-to-event approach, nor does it report censoring rules or missing-data methods.

What do the planning assumptions mean?

In general, a sample-size calculation is a planning exercise: it asks how much information might be needed to detect an effect under chosen assumptions. The registry’s stated planning illustration uses a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation; it describes the target effect as a stated fraction of the observed effect. This is not evidence that the retrospective study itself used those assumptions, and it is not observed power. The record describes the study as single-arm, so the two-arm assumptions belong to the planning illustration rather than a reported randomized design. No calculated sample-size values are included in the registry information available for this analysis.

In general, observed power is not a substitute for an uncertainty interval around an observed estimate. A planning calculation should not be interpreted as demonstrating that a completed study had adequate or inadequate power, especially when the outcome estimate and analysis details are unavailable. The assumptions and role of the illustration can be stated, but the registry record does not report a sample-size justification for the study itself.

Why might over-dispersion matter?

In general, over-dispersion occurs when the variability in data is greater than a statistical model assumes. If a model does not account for that extra variability, it can make estimates appear more precise than warranted. It can arise in some clustered or repeated-event settings, depending on the outcome and model. No over-dispersion assessment or model is reported in the registry record, and the percentage endpoint alone does not establish that such a model was used. This is a general statistical consideration, not a reported feature of this analysis.

What does absence of reported analyses imply?

The record lists 13 outcome measures and provides outcome definitions, but reports no analysis entries. This means that the registry information does not support a detailed account of how estimates were calculated, how uncertainty was handled, or whether prespecified analyses were followed. It does not establish that no analysis occurred outside the registry; it means the analysis is not reported in the registry record. Interpretation should therefore remain descriptive and limited to the information that is actually reported.

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("PAD Cohort")
n      <- c(145)
events <- c(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  PAD Cohort  145  0  0.0  0.0  2.5  0.0  2.6  0.0  2.5

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists 13 outcome measures across the PAD, AAA, and dialysis access cohorts. Several listed outcomes cover related safety or performance domains, including adverse events, patency, limb salvage, amputation-free survival, and infection requiring reoperation. When multiple outcomes are assessed, the chance of at least one apparently notable result can increase if each is tested separately. In general, multiplicity procedures can address this issue, but the appropriate approach depends on the questions and analysis plan. No multiplicity adjustment, testing hierarchy, or prespecified distinction between confirmatory and exploratory outcomes is reported in the registry record.

The primary safety endpoint is defined for the PAD cohort, but its result is not reported. The record also provides no analysis entries. It is therefore not possible to determine whether the listed outcomes were tested, whether any findings were selected for reporting, or how the analyses treated the collection of endpoints. The presence of multiple outcomes should not be read as evidence that all were analyzed in the same way.

Missing-data methods are also not reported in the registry record. Because the study is a retrospective chart review with data collected for up to 5 years after the index procedure, record availability and follow-up duration may vary. In general, missing outcome status can affect a percentage estimate if the participants with unavailable information differ from those whose status is known. The registry information does not describe how incomplete records, loss to follow-up, or unknown outcome status were handled. It also does not report analysis populations beyond the cohort descriptions and adverse-event at-risk counts. The impact of missing data and the exact population used for each endpoint therefore cannot be assessed.

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

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: vascular access site thrombosis (17.1%), thrombosis in device (15.2%), arteriovenous fistula site stenosis (8.9%), unknown cause of death (8.3%), device occlusion (8.3%).

The registry reports serious and other adverse-event counts separately for the PAD, AAA, and dialysis access cohorts, alongside a death count for each cohort. For PAD, the serious-event category records 145 at risk and 130 affected; the other-event category records 145 at risk and 8 affected, with 54 deaths. For AAA, the corresponding figures are 65 at risk and 50 affected for serious events, 65 at risk and 11 affected for other events, and 12 deaths. For dialysis access, the figures are 146 at risk and 101 affected for serious events, 146 at risk and 12 affected for other events, and 27 deaths. These are registry counts, not a randomized comparison.

The most frequently listed serious adverse-event terms include vascular access site thrombosis at 17.1%, thrombosis in device at 15.2%, arteriovenous fistula site stenosis at 8.9%, unknown cause of death at 8.3%, device occlusion at 8.3%, and stent thrombosis at 8.2%. The registry information does not give enough detail to interpret these term percentages as device-attributable risks or to determine their exact denominators. A listed event term does not by itself demonstrate that the device caused the event. The registry record does not report the full coding, attribution, or counting conventions for these figures, so they are best read as descriptive safety reporting.

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

The record establishes that a multicenter, single-arm retrospective registry was conducted to review clinical performance and safety of GORE-TEX® Vascular Grafts and GORE® PROPATEN® Vascular Graft across PAD, AAA, and dialysis access indications. It also defines a primary safety outcome for the PAD cohort: the percentage of participants with device-related seroma or infection, with data collected retrospectively for up to 5 years after the index procedure. These registry entries describe the study question and its setting.

The posted information does not report the primary endpoint estimate or its 95% confidence interval. It therefore does not show the recorded frequency of that endpoint or how precise an estimate would be. The adverse-event counts and listed event terms offer descriptive information, but they do not replace the primary endpoint result and do not support a treatment-effect comparison. No analysis entries are reported.

In general, a registry can document clinical experience and identify patterns that merit further study. A retrospective, single-arm record does not by itself establish what would have occurred under another device or treatment. Without a like-for-like comparison, observed outcomes cannot isolate a causal device effect. This limitation is particularly important when interpreting event attribution, since the endpoint definition involves investigator judgment for seroma and the record does not describe detailed attribution rules for all adverse events.

The three cohorts address different procedures and conditions, so their event counts should not be interpreted as direct comparisons. The registry’s stated follow-up extends for up to 5 years, but the completeness and duration of follow-up for each participant are not reported. The record also does not report methods for handling missing records, the analysis populations, or multiplicity. These gaps restrict conclusions about the size, precision, and robustness of any outcome estimate.

Accordingly, the registry record supports a description of the design, outcome definitions, cohort-specific safety counts, and listed serious-event terms. It does not, in the information reported, provide the numerical primary result needed to assess its observed magnitude or uncertainty. It also does not establish comparative efficacy or causation. Those distinctions are necessary when reading both the endpoint definition and the descriptive safety information.

14. Why This Trial Matters Statistically

Statistically, this registry illustrates why a clearly named endpoint is only one part of interpreting a clinical study. The primary PAD outcome is defined in clinical terms and includes an explicit device-related attribution for seroma, but the observed percentage and 95% confidence interval are not reported in the registry record. Without the estimate and its uncertainty, readers cannot assess how often the event was recorded or how precisely that frequency is known.

The design also illustrates the difference between describing outcomes and estimating a comparative treatment effect. A multicenter, retrospective, single-arm registry can capture clinical experience across PAD, AAA, and dialysis access settings. It does not provide a randomized or like-for-like control group in the reported design. The three cohorts represent different indications and procedures, so comparisons among them would not serve as a substitute for a controlled comparison.

Safety data also require attention to definitions and denominators. The registry gives cohort-specific at-risk and affected counts, death counts, and frequently listed serious-event terms. Those figures can inform a descriptive reading, but the counting conventions and attribution details are not fully reported. Percentages for individual terms should not automatically be interpreted as device-caused risks.

Finally, the record lists 13 outcome measures but no analysis entries. This leaves important statistical questions unanswered, including how incomplete follow-up was handled, whether outcomes were analyzed as proportions or with time-to-event methods, and how multiple outcomes were treated. These are not technical details separate from the results: they shape the meaning, precision, and reliability of estimates. The registry is therefore informative about its clinical scope and endpoint definitions, while the absence of reported primary results and analytical detail limits statistical 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.

Several limitations are specific to the information reported for this registry. First, the record defines a primary safety endpoint for the PAD cohort but does not report its observed percentage or 95% confidence interval. This prevents assessment of both the event frequency and the precision of the estimate. Although the study status is completed, completion status does not itself provide the missing endpoint result.

Second, the study is described as a retrospective, single-arm chart review. A control group suitable for a direct comparison is not reported, and allocation is not stated. The registry cannot, on the reported design information alone, distinguish device-related effects from differences in patient characteristics, procedure, clinical course, or follow-up. The cohorts also cover distinct indications and should not be interpreted as interchangeable comparison groups.

Third, follow-up is described as extending for up to 5 years after the index procedure, but the record does not report participant-level follow-up duration, completeness, censoring, or handling of missing records. For retrospective data, these details matter because an event may not be recorded or may not be observable if records are incomplete. The exact denominator used for the primary endpoint is not reported.

Fourth, the record lists 13 outcome measures but no analysis entries. It does not report methods for endpoint estimation, multiplicity, missing data, or analysis populations. The adverse-event counts and serious-event term percentages are descriptive, but the detailed counting and attribution rules are not reported in the registry record. These limitations prevent a more complete evaluation of how the safety information was assembled and analyzed.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Retrospective Post-Market Clinical Follow-Up Study of GORE-TEX® Vascular Grafts and GORE® PROPATEN® Vascular Graft in Peripheral Artery Disease, Aortic Aneurysms, and Dialysis Access — NCT05124184.
• Registry record last updated 2025-05-09; status last verified 2025-04.
• Results first posted 2025-05-09.
• 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

NCT05124184 is a completed, multicenter, single-arm retrospective registry based on chart review, sponsored by W.L.Gore & Associates. The listed start date is 2022-01-24 and the primary completion date is 2024-07-22. Enrollment is reported as 356. The registry covers PAD, AAA, and dialysis access in end-stage renal disease and names GORE-TEX® and GORE® PROPATEN® vascular grafts among the devices of interest.

The primary outcome is the percentage of participants in the PAD cohort with device-related seroma or infection, assessed from retrospective data collected for up to 5 years after the index procedure. A 95% confidence interval is the stated dispersion measure. The primary outcome estimate and interval are not reported in the registry record, and no analysis entries are reported. Cohort-specific adverse-event counts and serious-event terms are included, but the record does not report detailed analysis, missing-data, or multiplicity methods.