Magnetic Anastomosis Device Relief of Malignant Gastric Outlet Obstruction: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Magnetic Anastomosis Device Relief of Malignant Gastric Outlet Obstruction (NCT00487552), a na na study. The primary outcome is Success Rate Associated With the Creation of a Gastro-jejunal Anastomosis Using the Cook Magnetic Anastomosis Device With Trans-anastomotic Deployment of a Gastro-jejunal or Duodenal Stent.

2. Clinical Question

3. Trial Design

The registry record describes a single-group, interventional device study sponsored by Cook Group Incorporated. Its listed intervention is the Cook Magnetic Anastomosis Device with Stent, used for palliative treatment of gastric outlet obstruction. The condition is gastric outlet obstruction, and the study summary specifies obstruction caused by malignancy. No separate control arm or like-for-like comparison is described.

Enrollment is listed as 18. The study status is terminated. The record lists a start of 2008-01 and primary completion of 2009-01. These entries describe the study timeline and status; the reason for termination is not reported in the registry record.

The phase is listed as NA, allocation as NA, and masking as none. In practical terms, the record does not describe a phase classification, randomized allocation, or masking. Those entries should not be taken to imply a concealed comparison: the study is specifically identified as single-group, with no comparator listed.

The primary outcome is a participant count for procedural success, with a timeframe of approximately 8-10 days. The registry record lists two outcome measures, but only the primary outcome details appear in the registry entries. The other outcome measure is not described, and no analyses are reported. The record does not provide a protocol-level account of eligibility, treatment delivery, follow-up beyond the primary timeframe, or the statistical analysis plan.

A sample-size planning description refers to a hypothetical two-arm illustration with equal allocation, a two-sided significance level of 0.05, and a normal approximation. That is not the design of the registered study, which is single-group, and the description does not establish how the trial enrollment was chosen. The justification for enrollment is 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

Reasons for not completing this period:

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 Success Rate Associated With the Creation of a Gastro-jejunal Anastomosis Using the Cook Magnetic Anastomosis Device With Trans-anastomotic Deployment of a Gastro-jejunal or Duodenal Stent, measured over Approximately 8-10 days.

The primary endpoint counts participants meeting a defined procedural success criterion. Success requires placement of the gastric and jejunal magnets, creation of the anastomosis, and deployment of a gastro-jejunal stent. The stated measurement unit is participants, and the timeframe is approximately 8-10 days.

This endpoint focuses on completion of the specified procedure rather than a comparison of outcomes between treatment groups. General statistical context: a clearly defined procedural endpoint can describe whether the intended technical steps were completed in the study population. It does not, by itself, establish how durable the anastomosis was, whether symptoms changed, or how outcomes compare with another approach; those questions require relevant reported measures and analyses.

The registry record does not report the number of participants who met the success definition, a proportion, or an uncertainty interval. It also does not provide further detail about how patency was assessed, how unsuccessful or incomplete procedures were classified, or how participants without an endpoint assessment were handled. Consequently, the endpoint definition can be described, but its observed result and precision cannot be evaluated from the reported information.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The study is described as single-group. General statistical context: a single-group study summarizes outcomes in participants who receive the intervention, without a concurrent treatment arm for direct comparison. A count or rate from such a study can describe what occurred in that group, but it does not provide the same basis for estimating a between-group treatment contrast as a randomized comparison. In this record, the primary outcome is defined, but its observed count is not reported.

What does a participant count convey?

The primary measure is the number of participants meeting the procedural success definition. A count is an absolute summary. To interpret it as a success rate, readers also need the relevant number of participants assessed for the endpoint and a clear account of how missing or unevaluable outcomes were handled. Those details are not reported in the registry record. The enrollment figure alone should not be assumed to be the endpoint denominator.

General statistical context: an uncertainty interval around a proportion describes the range of values reasonably compatible with the observed data under a specified statistical method. It can communicate how imprecise an estimate may be, particularly when the study population is limited. No primary endpoint count or interval is reported, so the precision of procedural success cannot be assessed from this record.

Why does the design matter?

Because there is no comparator, any reported result would describe the treated group rather than a relative difference between treatments. General statistical context: comparisons are vulnerable to confounding when treatment assignment is not randomized, because groups may differ in ways that also affect outcomes. Here, the record does not describe a comparison group at all. It is therefore not appropriate to interpret the study as estimating comparative efficacy or a causal effect against another treatment.

The record lists allocation as NA and masking as none. These entries do not add a control group or establish a blinded assessment process. The methods for assessing procedural success, including any independent review, are not reported in the registry record. That absence limits the ability to judge how consistently the endpoint would have been classified.

What does the planning description mean?

The planning description specifies a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation for an illustrative sample-size calculation. It also says the target effect is expressed as a stated fraction of the observed effect. These are assumptions for a planning illustration, not evidence that the registered single-group study used a two-arm design. The record does not report the trial's own sample-size justification or a planned analysis supporting enrollment of 18.

General statistical context: a sample-size calculation estimates how much information a proposed design may provide under selected assumptions. Its result depends on the assumed effect, outcome variability, significance level, power target, and design. A planning calculation is not an observed outcome, and it is not observed power. The planning description in this record does not supply a basis for treating an unreported endpoint result as statistically conclusive.

The record contains no analysis results. In particular, no test statistic, p-value, confidence interval, adjusted estimate, or model specification is reported. The methods used to analyze the primary outcome are not reported in the registry record. The record also does not state whether any interim analyses occurred; their presence or absence cannot be inferred from the lack of posted analyses.

How should adverse-event counts be understood?

The adverse-event summary distinguishes serious events from other events and lists a number at risk and a number affected for each. General statistical context: such counts describe the listed safety population and event classification, but interpretation depends on consistent definitions, follow-up, and denominators. The record lists 12 at risk for each summary, but does not explain how that safety population relates to enrollment of 18 or provide additional detail on event collection and follow-up. The serious-term percentage for Death is also not explained by a participant-level denominator in the record.

Overall, the statistical information is insufficient to reproduce or assess an endpoint analysis. The outcome definition and selected safety counts are useful descriptive elements, but the absence of outcome results, analysis methods, and population details prevents evaluation of estimates, uncertainty, or sensitivity to analytic choices.

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("Magnetic Anastomosis Device (MAD) With Stent")
n      <- c(18)
events <- c(12)
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  Magnetic Anastomosis Device (MAD) With Stent  18  12  66.7  41.0  86.7  43.7  83.7  43.4  83.7

11. Multiplicity, Missing Data and Analysis Populations

The registry lists two outcome measures, but the available information describes only the primary procedural success measure. The other outcome and its timing are not reported in the registry record. No analyses are reported, and no multiplicity strategy is described. It is therefore not possible to determine whether multiple outcomes or statistical tests were planned, whether any adjustment was intended, or how the primary outcome was prioritized in analysis beyond its registry designation.

The registry record does not report missing-data methods, the number of participants with endpoint assessments, or whether all enrolled participants were included in an analysis. It does not identify an intention-to-treat, per-protocol, or other analysis population. No rules for classifying an incomplete procedure, a missing assessment, or a participant who did not complete follow-up are reported. These omissions matter because the primary outcome is a participant count and its denominator depends on how outcome availability and analysis eligibility are defined.

The study is listed as terminated, but the reason and timing relative to outcome collection are not reported in the registry record. No interim analyses or stopping rules are described. Their existence or absence should not be inferred. Without these details, readers cannot assess whether outcome collection or analysis may have been affected by early termination, or whether any decisions depended on accumulating results.

General statistical context: multiplicity refers to the risk of misleading findings when several outcomes or tests are considered, while missing-data methods affect how incomplete observations contribute to an estimate. The record does not provide enough information to assess either issue for this study.

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: death (66.7%).

The safety group is titled Magnetic Anastomosis Device (MAD) With Stent. The registry lists 12 participants at risk for serious adverse events and 10 affected. For other adverse events, it lists 12 at risk and 4 affected. These are the posted counts; the record does not provide additional detail on event definitions, follow-up duration, or whether a participant could contribute to more than one event category.

The record lists Death at 66.7% among the top serious terms. The death-count field is not populated, and the registry record does not explain the denominator or whether this percentage refers to participants or events. It should not be read as a participant death rate or converted into a death count. The meaning of this percentage is not reported in the registry record.

Enrollment is listed as 18, while the safety summaries list 12 at risk. The record does not explain the difference between these figures. Consequently, the safety counts should be interpreted using their stated at-risk group rather than assuming all enrolled participants were included. They describe the posted safety summary, but do not establish a comparative safety profile or quantify risk relative to another treatment.

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

The record identifies a specific procedural question: whether the Cook Magnetic Anastomosis Device with stent can be used to create an anastomosis, with success requiring magnet placement, anastomosis creation, and stent deployment. It also identifies an intended assessment timeframe of approximately 8-10 days. These details clarify what the primary outcome was intended to capture.

However, the registry record does not report the observed primary outcome count, a success rate, or an uncertainty interval. The number of outcome measures is listed as two, but the other measure is not described in the available information. No analyses are reported. The record therefore does not establish how often the defined procedure was successful or how precisely that result was estimated.

The single-group design supplies no comparator for judging relative outcomes. Even if a procedural result were available, a result from one treated group would not by itself show how outcomes compare with another approach. The study status is terminated, but the reason is not reported in the registry record, and the status alone does not explain the endpoint or safety findings.

The adverse-event counts show that 10 of 12 listed participants at risk were affected by serious adverse events, and 4 of 12 were affected by other adverse events. These summaries do not provide a controlled comparison. The Death term listed at 66.7% has no explained denominator, and a death count is not reported in the death field. It cannot support a clear estimate of participant mortality.

In short, the registry record documents the intended procedure, the definition and timing of its primary endpoint, the single-group design, and selected safety counts. It does not report the primary result, comparative evidence, endpoint precision, or enough analytic detail to draw broader conclusions. No claim about benefit or lack of benefit follows from the missing result.

14. Why This Trial Matters Statistically

This study illustrates why a clearly stated endpoint is not the same as a reported result. The registry defines procedural success through a sequence of technical steps and gives an approximate assessment timeframe. That definition helps readers understand what investigators intended to measure. But without the number of participants meeting the definition and the endpoint denominator, the central outcome cannot be quantified.

The single-group design also sets an important boundary on interpretation. It can describe outcomes in the treated group if those outcomes are reported, but it does not provide a concurrent control for estimating a comparative effect. A reader should distinguish a procedural feasibility question from a question about relative benefit or risk. The registry's design does not support the latter comparison.

The safety information demonstrates a separate reporting challenge. The serious and other adverse-event summaries list 12 participants at risk, while enrollment is 18, and the reason for this difference is not explained. The serious-term listing for Death gives a percentage without a clear denominator, while a death count is not reported in the corresponding field. These details limit even straightforward descriptive interpretation.

Finally, the terminated status is informative as a status label but not as an explanation. Without a reported reason for termination, analysis population, missing-data approach, or primary endpoint result, readers cannot determine whether the registered question was answered. The statistical lesson is to keep design, endpoint definition, outcome reporting, and interpretation distinct: the first two are described, while the result and its precision are not reported in the registry record.

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 principal trial-specific limitation in the registry record is the absence of a reported primary endpoint result. Although the success definition and approximate timeframe are specified, the number of participants who met the definition, the number assessed, and any uncertainty estimate are not reported. As a result, the main procedural outcome cannot be summarized quantitatively.

The single-group design has no listed comparator, so it cannot support a direct relative comparison. The registry record does not give further details of the participant selection criteria, baseline characteristics, procedure delivery, or assessment procedures. The absence of those details restricts assessment of how representative the enrolled group was and how consistently the endpoint was measured.

The record lists enrollment of 18 and 12 participants at risk in each safety summary, without explaining the relationship between those populations. It does not state why the study was terminated. It also does not report the analysis population, missing-data handling, interim analyses, or a statistical analysis plan. These are not details that can be reconstructed from the status or outcome definition.

Safety interpretation is limited by the unclear meaning of the Death term listed at 66.7% and the lack of a reported death count. The record does not identify the denominator for that percentage or clarify whether it represents participants or events. The listed serious and other adverse-event counts do not establish comparative risks, since no control group is described.

Finally, two outcome measures are listed, but only the primary measure is described in the available information. Multiplicity handling and the other outcome's results are not reported in the registry record. Together, these limitations leave the design and intended primary measure more interpretable than the trial's actual outcome evidence.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: Magnetic Anastomosis Device Relief of Malignant Gastric Outlet Obstruction — NCT00487552.
• Registry record last updated 2017-08-23; status last verified 2017-07.
• Results first posted 2012-07-27.
• 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.

19. Record Summary

The registry record describes a terminated, single-group device study sponsored by Cook Group Incorporated, with enrollment of 18. The intervention is the Cook Magnetic Anastomosis Device with Stent for palliative treatment of malignant gastric outlet obstruction. The listed start is 2008-01 and primary completion is 2009-01; the reason for termination is not reported in the registry record.

The primary endpoint is a participant count for procedural success, defined by magnet placement, creation of the anastomosis, and stent deployment, assessed at approximately 8-10 days. The primary endpoint result and analyses are not reported. Safety summaries list 10 serious adverse-event-affected participants among 12 at risk and 4 participants affected by other adverse events among 12 at risk. The Death term is listed at 66.7%, but its denominator is unclear and a death count is not reported.

There is no comparator group. The registry record does not report the reason for termination, analysis population, missing-data methods, or the trial's own sample-size justification.