Evaluation of an Endoscopic Suturing System for Tissue Apposition in Colonic Polypectomy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Evaluation of an Endoscopic Suturing System for Tissue Apposition in Colonic Polypectomy (NCT00553436), a na na study. The primary outcome is Numbers of Participants With Successful Deployment of Tissue Apposition System (TAS).

2. Clinical Question

3. Trial Design

This completed study evaluated the Tissue Apposition System (TAS) device in colonic polypectomy. Its stated purpose was to assess whether the surgical site in the bowel wall could be sewn closed in the colon or intestine after removal of a benign polyp according to standard of care. The record describes one group: all enrolled subjects were treated with the TAS device. Enrollment was 7.

The study model is single-group, and allocation is listed as NA. Masking is listed as none. There is no separate control arm, so the record does not support a randomized or like-for-like treatment comparison. The primary outcome was assessed at the time of surgery. Secondary outcomes concern successful deployment of tissue anchors and an associated knotting element for tissue closure after EMR, and durable tissue apposition at three months after EMR.

The recorded start was 2007-11, primary completion was 2009-04, and status is completed. The sponsor is Ethicon Endo-Surgery. The phase is listed as NA. Further details about the protocol, site count, eligibility criteria, recruitment process, or the timing of other assessments are not reported in the registry record.

Because the study has one treated group and no comparator, its design can describe recorded device deployment and other reported outcomes in the enrolled participants. It cannot by itself establish how those outcomes compare with an alternative approach. The registry record does not state a statistical plan or a sample-size justification for the original study.

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.

Before assignment: Non-randomized. Patients were considered for enrollment based on inclusion / exclusion criteria and were offered the opportunity for enrollment. Those that signed informed consent were enrolled.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: All enrolled subjects were analyzed

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 Numbers of Participants With Successful Deployment of Tissue Apposition System (TAS), measured over At The Time of Surgery.

The primary endpoint is the number of enrolled participants with successful deployment of the Tissue Apposition System (TAS). It is described as being assessed at the time of surgery, and the analysis population is listed as all enrolled subjects. This is a count endpoint: it records how many participants met the stated deployment criterion rather than measuring a continuous quantity or comparing groups.

For a device intended to bring tissue together, successful deployment is a direct measure of whether the device could be deployed as intended during the procedure. It is therefore relevant to the study’s stated technical question. It is not, by itself, a measure of lasting closure, healing, symptoms, or other clinical outcomes. The registry lists durable tissue apposition at three months as a separate secondary outcome, underscoring that deployment and later durability are distinct questions.

The record does not report the primary endpoint result, a definition of the criteria for “successful,” or a confidence interval around the result. It therefore does not allow readers to determine how many participants met the endpoint or how precisely the rate of successful deployment was estimated. No success count or success rate should be inferred from enrollment or from the safety figures.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

Statistical methods should match the outcome type, study design, and question. The registry describes the primary outcome as a number of participants with successful deployment, and the study as a single group. It lists no statistical analyses. The specific analysis method used for the primary endpoint, any interval estimation, and any prespecified statistical plan are not reported in the registry record.

What does a count endpoint mean?

General explanation: a count of participants with an event records how many people meet a defined outcome. It is different from a measurement such as time, length, or a score. To interpret a count, readers need both the outcome definition and the number assessed. For a proportion, the denominator must also be clear. In this study, the record identifies all enrolled subjects as the primary analysis population, but it does not report the count meeting the primary endpoint. It also does not describe the detailed criteria used to judge deployment as successful.

A count can describe what happened in the enrolled group, but alone it does not quantify precision. An interval estimate can communicate how uncertain a proportion may be, given the data and method. General explanation: with limited observations, estimates can be imprecise; an interval may make that uncertainty visible. No primary endpoint interval is reported in the registry record, so the precision of the deployment result cannot be assessed from the record.

What can a single-group design estimate?

General explanation: a single-group study can describe outcomes in the group observed. A control group provides a reference for estimating a between-group contrast, subject to the study design and analysis. Because this study has no separate comparator, there is no randomized between-group estimate to interpret. Its primary question is descriptive: how many enrolled participants had successful device deployment at surgery. The record does not report that number.

The registry lists allocation as NA and masking as none. These entries do not establish additional details about how participants were selected, how outcome judgments were made, or how the study was conducted. Such details are not reported in the registry record. The record also does not state whether any outcome assessment was independently reviewed or whether deployment criteria were prespecified.

What is the role of secondary outcomes?

Secondary outcomes address questions beyond the primary endpoint. The listed outcomes concern successful deployment of tissue anchors and an associated knotting element, and durable tissue apposition at three months after EMR. These outcomes concern different aspects or time points of the procedure. They should not be treated as substitutes for the primary outcome, and a successful deployment result would not automatically establish durable apposition. The results for these secondary outcomes are not reported in the registry record.

General explanation: when a study examines multiple outcomes, the chance of obtaining at least one apparently unusual result can increase if each is tested separately without a plan for interpreting multiple tests. A multiplicity strategy may control or otherwise address that issue. The registry record does not report inferential analyses or a multiplicity strategy. Since there are no posted outcome analyses in the record, there are no reported p-values to interpret or adjust.

How should planning calculations be read?

General explanation: a sample-size calculation is a planning exercise based on assumptions about the effect to detect, variability, allocation, and error rates. It is not evidence that a study had a particular probability of finding a result after it was conducted. The sample-size assumptions described for the planning illustration specify a two-sided significance level of 0.05, equal allocation between two arms, a normal approximation, and an effect defined as a stated fraction of the observed effect. The record also distinguishes participants per arm for non-time-to-event outcomes from total events for time-to-event calculations.

Those planning assumptions do not change the actual single-group design described for this study. A two-arm planning illustration is not a description of the study’s enrolled design, and planning estimates are not observed power. The original study’s sample-size justification and design assumptions are not reported in the registry record. The primary outcome result needed to interpret an effect-based planning illustration is also not reported in the registry record.

What analysis details remain unknown?

The registry lists zero analyses. It does not report a statistical model, covariate adjustment, hypothesis test, confidence interval method, handling of missing outcomes, or sensitivity analysis. It also does not describe interim analyses or stopping criteria. General explanation: such details help readers understand how estimates were produced and what assumptions support them. Without those details—and without the outcome result—an independent recalculation or evaluation of statistical precision is not possible from the registry record.

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("Enrolled Subjects Treated With Tissue Apposition S")
n      <- c(7)
events <- c(6)
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  Enrolled Subjects Treated With Tissue Apposition S  7  6  85.7  42.1  99.6  48.7  97.4  47.3  96.8

11. Multiplicity, Missing Data and Analysis Populations

The registry record lists a primary outcome and two secondary outcomes. The primary outcome concerns successful deployment of the TAS device at surgery. The secondary outcomes concern successful deployment of tissue anchors and an associated knotting element after EMR, and durable tissue apposition at three months after EMR. Results for these outcomes are not reported in the registry record.

Multiplicity arises when multiple outcomes or statistical tests are considered. General explanation: without a prespecified approach, separate tests can make chance findings more likely across a set of comparisons. The registry record does not report inferential analyses, a testing hierarchy, or a method for addressing multiplicity. Since no outcome analyses are listed, there are no reported p-values or confidence intervals to interpret in light of multiplicity.

The primary analysis population is described as all enrolled subjects. The record does not provide a participant flow account or say whether all enrolled participants had evaluable primary or secondary outcomes. It does not describe missing-data handling, exclusions from specific outcome assessments, or imputation. The primary outcome result is not reported, so the record also does not establish whether outcome data were complete.

General explanation: missing outcomes can affect interpretation if the people without measurements differ from those with observed results. Understanding the extent and handling of missingness is therefore important when interpreting a study estimate. In this record, the relevant details are not reported in the registry record. The stated analysis population should not be taken as proof that every listed outcome was observed for every participant.

12. 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 5% reporting threshold.

Most frequent serious adverse event terms

Most frequent non-serious adverse event terms

Serious events with the highest arm-level rate: spinal stenosis (14.3%), chest pain (14.3%).

The registry lists serious adverse events for a group titled Enrolled Subjects Treated With Tissue Apposition System (TAS). Serious adverse events affected 2 participants among 7 at risk. Other adverse events affected 6 participants among 7 at risk. These are descriptive counts in the registry record; they do not establish whether an event was caused by the device or procedure.

The two serious-event terms listed are Spinal Stenosis and Chest Pain, each reported as 14.3%. The record does not explain whether these terms refer to separate participants, whether a participant could have more than one event, when the events occurred, or how they were assessed. It also does not provide further event narratives. Deaths are not reported in the registry record.

General explanation: adverse-event counts describe reported events or affected participants according to the record’s classifications. They do not by themselves show causation, comparative risk, or the likelihood of an event in a broader population. In this single-group study there is no control group for a direct safety comparison. The listed counts should therefore be read as descriptive registry information, not as evidence that the device did or did not cause an event.

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

The record establishes that a completed, single-group study evaluated the TAS device after removal of a benign polyp, with enrollment of 7. It identifies successful deployment at the time of surgery as the primary endpoint and names two secondary outcomes concerning tissue anchors and later apposition. It also records adverse-event counts in the treated group.

The record does not report the primary endpoint result or the results of either secondary outcome. Consequently, it does not establish how often deployment was successful, whether tissue apposition persisted at three months, or how those outcomes were distributed among participants. No estimate of the primary result’s precision is reported. The safety counts are descriptive and do not establish attribution to the device or procedure.

Because there is no separate comparator group, the design cannot provide a direct estimate of how outcomes differ from those under another approach. General explanation: an observed outcome in one group is not itself a comparative effect. Even complete outcome reporting would not make this study a randomized comparison.

The findings therefore have a bounded interpretation: the registry describes the study’s aim, design, endpoint definitions, and recorded safety counts, but it does not provide the outcome results needed to judge the stated deployment question. It would be inappropriate to infer the missing results from enrollment, the study’s completion status, or the adverse-event fields. Nor can the record support a claim about effectiveness or lack of effectiveness. Those conclusions would require relevant outcome data and, for comparative claims, an appropriate comparison.

14. Why This Trial Matters Statistically

This study raises a useful statistical distinction between whether a device can be deployed during a procedure and whether tissue apposition is maintained later. The primary endpoint addresses deployment at surgery; the secondary outcome concerning durable apposition at three months addresses a separate time point and aspect of performance. Keeping these outcomes distinct is important when translating a technical study question into measurable endpoints.

The single-group design also illustrates the difference between describing an observed group and estimating a comparative effect. With no control group, the study can be framed around outcomes among participants treated with the TAS device, but it cannot directly contrast those outcomes with another strategy. That design boundary affects what statistical conclusions are possible, regardless of the analysis method.

Reporting completeness is central to interpretation. The registry record states enrollment and describes the primary and secondary outcomes, yet it does not report their results or an analysis plan. As a result, readers cannot assess the primary outcome’s magnitude or precision from the registry record. The safety entries are available as descriptive counts, but do not resolve the missing efficacy outcome information or establish causality.

General statistical lesson: an endpoint definition, a study design, and a reported estimate each answer different questions. A well-described endpoint does not replace its result; a completed study status does not reveal its findings; and a count without uncertainty does not show how precisely an underlying rate is known. This record makes those distinctions especially visible.

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 most consequential limitation for interpretation is that the primary outcome result is not reported in the registry record. The secondary outcome results are also not reported. Without those results, the study’s stated questions about successful deployment and durable tissue apposition cannot be answered from the record.

The study is single-group, with no separate comparator. Its results, if reported, would describe outcomes among treated participants rather than provide a direct comparison with another approach. Enrollment was 7, so the study description concerns a limited group; the record does not provide information about how representative the enrolled participants were of other populations or settings.

The primary endpoint is described as successful deployment, but the operational criteria for success are not reported in the registry record. Further details about eligibility, participant characteristics, outcome assessment procedures, and completeness of outcome data are also not reported. The record does not describe missing-data methods, statistical analyses, a sample-size justification, or a multiplicity approach.

The safety information is limited to counts and listed terms. Event timing, narratives, attribution, and participant-level overlap between terms are not reported in the registry record. These limitations prevent stronger interpretation of the safety entries. Finally, the absence of a posted statistical analysis means that no inferential estimate or uncertainty measure can be evaluated from the registry record.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Evaluation of an Endoscopic Suturing System for Tissue Apposition in Colonic Polypectomy — NCT00553436.
• Registry record last updated 2010-04-27; status last verified 2010-04.
• Results first posted 2010-03-26.
• 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

NCT00553436 is a completed, single-group study sponsored by Ethicon Endo-Surgery. It evaluated the Tissue Apposition System (TAS) device for tissue apposition after removal of a benign polyp. Enrollment was 7; the recorded start was 2007-11, and primary completion was 2009-04. The primary endpoint was the number of participants with successful deployment at the time of surgery.

The registry record does not report the primary or secondary outcome results, and it lists zero analyses. Serious adverse events affected 2 participants among 7 at risk; other adverse events affected 6 among 7 at risk. The record does not provide a comparator group or a reported statistical analysis plan.