Angio-Seal Interventional Radiology (IR) Registry: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Angio-Seal Interventional Radiology (IR) Registry (NCT01222104), a registered phase not stated study. The primary outcome is Rate of Major Vascular Complications.

2. Clinical Question

This is a registry question about device use and complications in routine diagnostic and/or interventional radiology care, rather than a stated randomized comparison of closure strategies. The record identifies attempted and/or deployed Angio-Seal use and a separate category for procedures in which it was not deployed. Because allocation is not stated and the groups are not described as comparable, a contrast between them would not by itself establish that the device caused any difference in outcomes.

The primary endpoint is specified as the percentage of procedures with a major vascular complication, assessed through 30 days. The endpoint includes several clinically serious event types, from vascular injury requiring repair to bleeding, ischemia, infection, extended hospitalization, or death. The registry record does not give the observed number of primary events, the analyzed denominator, or an estimate of uncertainty. It therefore does not answer the event-rate question numerically.

3. Trial Design

The registry describes a clinical registry of St. Jude Medical Angio-Seal vascular closure devices following interventional radiology procedures. Its stated purpose was to collect data on standard-of-care use of the Angio-Seal Evolution and V-Twist Integrated Platform devices in diagnostic and/or interventional radiology patient populations. The recorded enrollment is 634, and the registry status is completed.

The study began in 2010-10, with primary completion recorded as 2011-05. The primary outcome is the rate of major vascular complications through 30 days. Secondary outcomes include time to hemostasis, minor vascular complications, and outcomes related to guided access mode and peripheral vascular disease. The record lists 11 outcome measures, but reports no analyses.

The recorded arm descriptions are “Angio-Seal attempted and/or deployed” and “Other method of closure” for the “Not deployed” group. The allocation method is not stated. The record’s design notes also caution that this is not a randomized comparison and that the arms are not a like-for-like control comparison. Accordingly, the registry can describe device use and reported events, but the arm labels alone do not establish a controlled treatment contrast.

The registry record does not report a detailed statistical analysis plan, the method used to select participants, the handling of repeat procedures, or whether enrollment was consecutive. It also does not report how the primary-outcome denominator was defined in the analysis, whether any follow-up procedures were used to ascertain events, or how missing follow-up was handled. These details cannot be inferred from the registry description.

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

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: 5 subjects underwent vascular closure with Angio-Seal on right and left sides.

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 Rate of Major Vascular Complications, measured over 30 days.

The primary endpoint is the rate of major vascular complications, expressed as a percentage of procedures, through 30 days after the procedure. An endpoint that combines several prespecified complications can capture a range of serious outcomes in a single summary. The record defines a major vascular complication as vascular injury requiring repair; permanent or intervention-requiring access-site nerve injury; access-site bleeding requiring transfusion; new ipsilateral lower-extremity ischemia requiring surgical intervention; retroperitoneal bleeding; generalized infection requiring prolonged hospitalization and/or intravenous antibiotics; an access-related complication causing an extended hospital stay; or death.

In general, a defined composite endpoint can be useful when separate events are uncommon or when a study aims to summarize several related harms. However, its overall rate does not show how often each component occurred, and components may differ in severity and clinical meaning. For that reason, component-level counts and clear event definitions are important when interpreting a composite. The registry record gives the definitions but does not report the primary event count, the denominator used for the percentage, or component-level primary-outcome results. The rate and its statistical precision are therefore not reported in the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry record names a primary outcome but does not report the analysis used to estimate it. The statistical interpretation is therefore limited: the endpoint definition and timeframe can be described, but the event rate, its uncertainty, and any comparison between groups cannot be reconstructed from the record. A statistical method should not be inferred just because the outcome is expressed as a percentage.

What does a rate describe?

In general, a rate expressed as a percentage uses an event count in relation to a defined denominator. For this primary endpoint, the stated unit is percentage of procedures. The denominator matters because the record also describes enrollment in subjects, and it notes that 5 subjects underwent closure on both right and left sides. Subject and procedure counts need not represent the same analysis unit. The registry record does not report the denominator used for the primary outcome or how repeated or bilateral procedures were handled. Without that information, a percentage cannot be interpreted or independently checked.

Why does precision matter?

In general, a confidence interval describes a range of values compatible with the observed data under the assumptions of the statistical method. It communicates uncertainty around an estimate; a point estimate alone does not. Precision depends on factors such as the event count, the denominator, and the analysis method. The registry record does not report a primary estimate or confidence interval, so neither the event rate nor its precision is available for evaluation.

What can a comparison between the groups establish?

In general, random allocation can help make groups comparable with respect to both measured and unmeasured characteristics. In observational registries, treatment or device use may be related to patient or procedural characteristics. If such characteristics also relate to complications, a simple difference between groups can reflect those differences as well as any association with the device. The record does not state an allocation method and explicitly says this is not a randomized comparison and the arms are not a like-for-like control comparison. It does not report an adjusted analysis that could address measured differences. A causal effect should not be inferred.

What does the adverse-event summary represent?

In general, safety summaries may count affected participants, events, or participants experiencing an event, and those units are not interchangeable. A person can experience more than one event, and a single event may meet more than one category. The record gives affected and at-risk fields for serious and other adverse events, but it does not describe whether counts refer to unique people or event occurrences, whether categories overlap, or how the term-specific percentages were calculated. Those details should be known before treating the figures as incidence estimates or comparing them with the primary endpoint.

How should planning calculations be understood?

In general, a sample-size calculation is a planning exercise based on assumptions about the effect to detect, the significance level, allocation, and statistical model. It is not a measure of the probability that a completed study detected a true effect. The planning description associated with the registry says its illustration uses the observed effect, a two-sided significance level of 0.05, equal allocation, and a normal approximation; it also distinguishes participant counts per arm from total event counts for time-to-event outcomes. No observed primary effect, numerical planning result, or trial-specific design justification is reported in the registry record. Any such illustration should be read as hypothetical planning, not as observed power or as evidence of a treatment effect.

The record lists 11 outcome measures and no analyses. It does not report the statistical tests, model specifications, covariate adjustments, confidence-interval methods, or software used. Those methods are not reported in the registry record, so statistical claims that depend on them cannot be verified.

10. Multiplicity, Missing Data and Analysis Populations

The registry record lists 11 outcome measures, including the primary major vascular complication outcome and secondary outcomes concerning hemostasis, minor complications, guided access, and peripheral vascular disease. It reports no analyses. The record does not state whether any multiplicity strategy was planned or used, such as controlling the chance of false-positive findings across several outcome tests. Without reported analyses, there are no outcome-specific estimates or tests to assess in any case.

Missing-data methods are not reported in the registry record. It does not say whether follow-up was complete through 30 days, how participants without outcome ascertainment were handled, or whether any imputation or sensitivity analysis was performed. The number enrolled does not establish the number with evaluable primary-outcome data. The primary endpoint is expressed per procedure, but the record does not report the analyzed procedure denominator or explain how subjects with more than one procedure contributed.

The analysis populations are also not defined beyond the descriptions of device use and the primary outcome’s stated population. The record does not report whether the primary analysis included all enrolled patients, only those with a deployed device, or another defined set. It does not state how attempted but undeployed devices or use of another closure method entered the primary analysis. These omissions limit the ability to assess selection, follow-up completeness, and the relevance of any analysis population to the registry’s intended question.

11. Safety Results

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

Other (non-serious) adverse events

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

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: death (1.6%), vascular injury requiring repair via surgery or other means (0.3%), retroperitoneal bleeding (0.3%), new ipsilateral lower extremity ischemia requiring intervention (0.2%).

The safety fields list 15 affected in the serious adverse-event category and 4 affected in the other adverse-event category, with 634 at risk for each. These should be read as the registry’s recorded fields, not as proof that each number represents a unique participant or a count of independent event occurrences; the record does not explain the counting convention.

The listed serious adverse-event terms include Death at 1.6%, vascular injury requiring repair via surgery or other means at 0.3%, retroperitoneal bleeding at 0.3%, and new ipsilateral lower-extremity ischemia requiring intervention at 0.2%. The record does not explain whether a person or event could appear under more than one term, how term-specific percentages were derived, or how those terms map onto the primary endpoint analysis. The percentages should therefore not be added together or treated as a single event rate.

These safety summaries are distinct from the primary endpoint, which is defined as major vascular complications through 30 days. The registry record does not report the primary endpoint result or a full account of safety ascertainment and follow-up. The safety figures describe what was entered in the adverse-event fields; they do not by themselves establish a comparative risk or a causal relationship to device use.

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

The registry record establishes that the study was intended to collect data on standard-of-care use of Angio-Seal devices in diagnostic and/or interventional radiology procedures. It defines a primary outcome of major vascular complications through 30 days and lists several secondary outcomes. It also records enrollment and summarizes selected adverse-event fields. These details describe the registry’s scope, but they do not provide a numerical result for the primary clinical question.

Because no primary outcome count, percentage, denominator, or confidence interval is reported, the rate of major vascular complications cannot be estimated from the posted results. The absence of a reported analysis is not evidence that no complications occurred, nor does it establish that complications were common. It means the registry record does not provide the result needed to characterize that outcome.

The study is not described as a randomized comparison. Allocation is not stated, and the record cautions that the device-use groups are not a like-for-like control comparison. Any observed group difference, if available elsewhere, would require careful consideration of selection and procedural differences before it could be interpreted as an effect of the device. The registry record does not report adjusted analyses or enough detail to evaluate such differences.

The serious and other adverse-event fields give limited safety information, but the event-counting rules and overlap among categories are not reported. Those fields cannot replace the specifically defined primary endpoint, and the term percentages should not be combined into an overall rate. Overall, the record documents a clinical registry question and some safety reporting, while leaving the main outcome result and its statistical uncertainty unreported.

13. Why This Trial Matters Statistically

This registry illustrates a basic statistical distinction between defining an outcome and reporting its result. The record provides a detailed definition of major vascular complications and a 30-day timeframe, but it does not report the event count, percentage, denominator, or uncertainty. A well-defined endpoint is necessary for interpretation, yet it cannot answer a clinical frequency question without an analyzed result.

It also highlights the importance of matching the unit of analysis to the endpoint. The primary measure is expressed per procedure, while enrollment is recorded in subjects. The note about 5 subjects having right- and left-side closure makes clear why a reader should not assume that participant and procedure counts are equivalent. The registry record does not explain how this issue was handled in analysis.

The nonrandomized registry design is another important statistical consideration. Device use in routine care is not described as randomly assigned, and the record warns that the groups are not like-for-like controls. This cautions against interpreting group contrasts as causal without an appropriate design and analysis. Finally, several outcomes are listed, but no analyses are reported and multiplicity handling is not described. Together, these features show why endpoint definitions, denominators, analysis populations, and transparent statistical reporting are essential for assessing clinical registry findings.

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 primary limitation for interpretation is that the registry record does not report the primary endpoint result. It gives no major-complication event count, percentage, analyzed denominator, or confidence interval. The listed enrollment does not resolve the missing procedure denominator, particularly because the primary endpoint is measured per procedure and the record notes bilateral closure in 5 subjects.

The record does not report how participants or procedures were selected, whether enrollment was consecutive, how follow-up was completed, or how missing outcome information was handled. It does not define the primary analysis population or explain how attempted but undeployed devices and other closure methods were treated in the endpoint analysis. These omissions prevent assessment of possible selection and follow-up biases.

The registry is not a randomized comparison, allocation is not stated, and the record says the groups are not a like-for-like control comparison. No adjusted analyses are reported. Differences between groups therefore cannot be attributed to the closure method on the basis of the available record.

Safety reporting is also limited: the record does not clarify whether affected counts represent unique participants or events, whether adverse-event categories overlap, or how the listed term percentages were calculated. Although 11 outcome measures are listed, no analyses are reported, and multiplicity methods are not described. The record does not provide a detailed statistical plan, sample-size justification, interim-analysis information, or methods for estimating uncertainty. Those items are not reported in the registry record.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Angio-Seal Interventional Radiology (IR) Registry — NCT01222104.
• Registry record last updated 2019-02-05; status last verified 2019-02.
• Results first posted 2014-11-19.
• 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 Angio-Seal Interventional Radiology Registry is recorded as completed, with enrollment of 634. Its stated purpose was to collect standard-of-care use data on Angio-Seal Evolution and VIP devices in diagnostic and/or interventional radiology populations. The primary outcome is major vascular complications through 30 days, expressed as a percentage of procedures. The registry record lists 11 outcome measures and no analyses.

The record describes an Angio-Seal attempted and/or deployed group and a “Not deployed” group using another closure method. Allocation is not stated, and the groups are not a like-for-like control comparison. Safety fields list 15 affected for serious adverse events and 4 for other adverse events, each with 634 at risk, alongside selected serious-event terms and percentages. The primary outcome’s event count, denominator, estimate, and precision are not reported in the registry record.