The SERI® Surgical Scaffold Use in Reconstruction Post Market Study for Tissue Support and Repair in Breast Reconstruction Surgery: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for The SERI® Surgical Scaffold Use in Reconstruction Post Market Study for Tissue Support and Repair in Breast Reconstruction Surgery (NCT01256502), a na na study. The primary outcome is Investigator Satisfaction Following Use of SERI® Surgical Scaffold at 6 Months.

2. Clinical Question

This question concerns investigators’ assessment of the scaffold after use, rather than a randomized comparison or a direct measure of patient satisfaction. The outcome is defined at the 6-month visit, while the registry also lists assessments of ease of use at placement and satisfaction at other time points as secondary outcomes. The record describes a post-market study intended to gather clinical experience in breast reconstruction. Its single-group structure means the stated primary question is descriptive: it asks how investigators rated satisfaction in the study population. It does not, by itself, estimate a difference between SERI® and another approach. The record identifies the analysis population, but gives no mean satisfaction score or dispersion for that population. Consequently, the scale definition and study population can be described, but the recorded evidence does not establish the level or precision of satisfaction ratings.

3. Trial Design

The SERI® Surgical Scaffold Use in Reconstruction Post Market Study for Tissue Support and Repair in Breast Reconstruction Surgery is registered as a completed, single-group device study. Its stated purpose was to obtain clinical experience with use of SERI® Surgical Scaffold for tissue support and repair in breast reconstruction. The record lists 160 participants as the enrollment and describes an implanted-participant group. It records breast reconstruction as the condition and SERI® Surgical Scaffold as the intervention.

The study has no separate comparator group. Allocation is listed as NA and masking as NONE. Phase is listed as NA. These registry entries do not describe a randomized allocation process or a masked comparison. The design therefore supports describing outcomes among participants who received the scaffold, but does not provide a direct treatment contrast with an alternative intervention or untreated group.

The registry dates the study start to 2010-10 and primary completion to 2012-10, and lists the status as COMPLETED. It reports that 139 participants, with 214 breasts implanted during Stage I breast reconstruction, formed the group from which the primary analysis population was drawn. The primary population consisted of 134 subjects and 205 breasts after four participants discontinued and one missed the 6-month visit.

The primary outcome is investigator satisfaction at 6 months following Stage I surgery and implantation. Two secondary outcomes concern investigator ease of use at placement during Stage I surgery and investigator satisfaction at other time points. Although the record identifies three outcome measures, it does not report numerical primary outcome results or analysis results. The statistical analysis plan, any sample-size justification, and any interim analyses 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.

Before assignment: Enrollment was defined as having signed the IRB-approved Informed Consent Form. 160 patients were enrolled, of which 139 were implanted with SERI® Surgical Scaffold.

Overall Study

Reasons for not completing this period:

Analysis population for the primary outcome, as defined in the registry: Of the 139 participants, 214 breasts, implanted with SERI® during Stage I breast reconstruction, 4 discontinued the study and 1 missed the 6-month visit, leaving 134 subjects, 205 breasts in the primary analysis population.

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.

Population: Subjects implanted with SERI® during their Stage I breast reconstruction surgery

6. Primary Endpoint

The registry lists the primary outcome as Investigator Satisfaction Following Use of SERI® Surgical Scaffold at 6 Months, measured over 6 months.

The primary endpoint is investigator satisfaction with SERI® Surgical Scaffold at 6 months after Stage I surgery and implantation. Satisfaction is measured on an 11-point scale, with 0 defined as very dissatisfied and 10 as very satisfied. The registry identifies the summary measure as a mean, with standard deviation as the measure of dispersion, and describes the unit as units on a scale.

A satisfaction rating is a way to capture an investigator’s overall assessment of the device after use. In general, a mean can describe the average rating across observations, while a standard deviation describes how spread out individual ratings are around that mean. The mean alone would not show whether ratings were tightly clustered or varied considerably; the accompanying dispersion measure helps describe that pattern. These are general interpretations of the statistical summaries named in the record.

The record does not report the mean satisfaction score or its standard deviation. It also does not report a confidence interval or another measure of uncertainty for the primary endpoint. Accordingly, the scale anchors and intended summary can be explained, but the actual distribution and precision of investigator ratings cannot be assessed from the registry record. This endpoint records investigator satisfaction; it should not be read as a patient-reported outcome or as a comparison with a control treatment.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The primary outcome is continuous in the sense that it is summarized as a mean on a rating scale. The registry names the mean and standard deviation as the summary statistics, but it does not provide their numerical values. General statistical explanation: the mean represents the average of the recorded ratings, and the standard deviation describes the typical spread of ratings around that average. A mean and standard deviation together convey more than a mean alone, but they do not show the full shape of the data. For example, they do not by themselves identify whether ratings cluster near one end of the scale or whether there are distinct groups of responses.

The endpoint uses an 11-point scale whose anchors are explicitly stated: 0 means very dissatisfied and 10 means very satisfied. A scale’s anchors help readers understand what its ends signify. The registry does not report how investigators were instructed to select a score, whether all scale values were used, or how ratings were distributed. Those details are not reported in the registry record and should not be assumed.

The sample unit deserves attention. The primary analysis population is reported as 134 subjects and 205 breasts, while the implanted group is reported as 139 participants and 214 breasts. These are counts of people and breasts, not the same unit. General statistical principle: when one person can contribute more than one body site or measurement, observations from the same person may be correlated. Treating correlated observations as independent can make uncertainty appear smaller than it is. The registry does not state whether satisfaction was rated per participant, per breast, or by another unit, and it does not describe any method for handling within-participant correlation. The method used is not reported in the registry record.

Precision is usually assessed with a confidence interval or another uncertainty measure. General explanation: a confidence interval gives a range of values compatible with the data and the assumptions of the analysis; a narrower interval indicates greater statistical precision than a wider interval. The registry record does not report a confidence interval for the primary outcome. Since it also omits the mean and standard deviation, the primary estimate’s precision cannot be assessed from the reported information.

There is no control arm in this single-group study. A one-group mean can describe the ratings recorded among participants, but it cannot on its own separate the effect of the device from other influences. General statistical principle: comparative effectiveness questions require a suitable comparison, and random allocation can help balance known and unknown influences between groups. This record lists allocation as NA and does not describe a randomized comparison. A causal contrast should not be inferred.

The record lists three outcome measures, including the primary satisfaction assessment and secondary assessments of ease of use at placement and satisfaction at other time points. When several outcomes are tested, multiplicity can make isolated statistically significant findings more likely by chance. General methods may address this through a prespecified hierarchy or adjustment, but neither the use of such a strategy nor the statistical analysis plan is reported in the registry record. No p-values or analysis results are listed.

Sample-size calculations and power require careful interpretation. General explanation: a planning calculation depends on assumptions about the effect to detect, variability, significance level, and design. Such a calculation is not evidence that an effect was observed, and it is not observed power. The record’s planning description refers to an illustration based on a fraction of an observed effect and specifies a two-sided significance level of 0.05, equal allocation, and a normal approximation. It also distinguishes participants per arm for ordinary outcomes from total events for time-to-event outcomes. This was described as a planning illustration, not the study’s own design justification. No numerical illustration results are reported in the registry record, and there are no two randomized arms in this single-group study. The actual sample-size justification is not reported in the registry record.

Finally, the record indicates zero registered analyses. That does not establish that no analyses were performed outside the registry; it means that analysis results are not reported in the registry record. No adjusted model, inferential test, interim analysis, or missing-data method can be characterized from the information recorded. Any interpretation should remain within the available descriptive details rather than filling these methodological gaps with assumptions.

10. Confidence Intervals for Each Arm

No two-arm comparison is shown for this trial, but each arm's mean can be given with a t-based 95% confidence interval computed from the posted mean, spread and number of participants.

R code and output

arm <- c("Implanted Participants")
n   <- c(134)
m   <- c(9.4)
sp  <- c(0.84)
sd  <- sp      # posted standard deviations
for (i in seq_along(n)) {
  se <- sd[i] / sqrt(n[i]); h <- qt(0.975, n[i] - 1) * se
  cat(sprintf("CARM|%s|%d|%.3f|%.3f|%.3f|%.3f\n", arm[i], n[i], m[i], sd[i], m[i] - h, m[i] + h))
}

CARM  Implanted Participants  134  9.400  0.840  9.256  9.544

11. Multiplicity, Missing Data and Analysis Populations

The record identifies a primary outcome and two secondary outcomes: investigator ease of use at the time of placement during Stage I surgery, and investigator satisfaction following use at other time points. It reports three outcome measures in total. Considering multiple outcomes can create multiplicity concerns when researchers conduct several statistical tests. General explanation: the more separate tests considered, the greater the opportunity for a chance finding unless the analysis plan accounts for that multiplicity. The registry does not report a testing hierarchy, adjustment method, or other multiplicity strategy. Whether any adjustment was planned or used is not reported in the registry record.

The primary analysis population is described as 134 subjects and 205 breasts. The registry states that, among 139 participants and 214 breasts implanted during Stage I reconstruction, four participants discontinued the study and one missed the 6-month visit, leaving that primary analysis population. The record does not explain the reasons for discontinuation, the circumstances of the missed visit, or whether other outcome-specific data were missing.

General explanation: missing-data methods can affect an estimate when outcome availability is related to participants’ ratings or other characteristics. Common approaches make different assumptions about the unobserved values, so the method and its assumptions matter. The registry does not state whether missing observations were excluded, imputed, or handled through another method. It also does not report sensitivity analyses addressing missing data. Those procedures are not reported in the registry record.

The analysis population is therefore identifiable by its reported counts, but the analysis rules and missing-data assumptions are not. No further inference about the missing observations or the effect of their absence is supported by the recorded information.

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: cellulitis (3.6%), capsular contracture associated with breast implant (2.2%), breast cancer (2.2%), device related infection (1.4%), pneumonia (1.4%).

The registry reports adverse-event figures for the implanted-participant group. It lists 139 participants at risk and 25 affected for serious adverse events, and 139 at risk and 107 affected for other adverse events. These are the counts recorded for the categories; the record does not provide further detail about event overlap or how repeated events were counted. The death count is not reported in the registry record.

The listed serious-event terms and their reported percentages are cellulitis, 3.6%; capsular contracture associated with breast implant, 2.2%; breast cancer, 2.2%; device related infection, 1.4%; pneumonia, 1.4%; and mastitis, 1.4%. These figures describe the terms and percentages recorded in the registry. The record does not specify in this information whether percentages refer to participants, events, or another denominator, so they should not be reinterpreted as event rates or used to infer counts.

General explanation: serious adverse events are safety outcomes, and their interpretation depends on definitions, follow-up duration, ascertainment, and the denominator used. A list of event terms does not establish that the device caused an event. The registry figures alone do not support a causal attribution, a comparison with another treatment, or conclusions about events not listed.

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

The study addresses investigator experience with SERI® Surgical Scaffold in breast reconstruction. Its main outcome was defined as investigator satisfaction at 6 months, measured on a scale from 0, very dissatisfied, to 10, very satisfied. The record also identifies a primary analysis population of 134 subjects and 205 breasts. These details establish what the outcome was intended to capture and who was included in the stated analysis population.

The registry does not report the numerical satisfaction result. As a result, the posted record does not show the average rating, the variation among ratings, or the precision of an estimate. It is not possible to tell from this record whether ratings tended toward one end of the scale, how consistent they were, or how uncertain the average might be. A scale definition is not itself an outcome result.

The single-group design also limits what the study can establish. The registry does not describe a control group or randomized allocation. A descriptive assessment of investigators’ ratings among scaffold recipients is not the same as evidence of a difference compared with another device or surgical strategy. General statistical principle: without an appropriate comparator, group outcomes cannot isolate the effect of an intervention from other factors that may influence the measured outcome.

The safety figures provide counts for serious and other adverse-event categories, along with percentages for listed serious-event terms. They do not, on their own, establish whether events were caused by the device or how the results compare with another population. The death count is not reported in the registry record.

Accordingly, the record supports a description of the study design, endpoint definition, analysis population, and recorded safety categories. It does not support a conclusion about the numerical level of investigator satisfaction, its statistical precision, or a comparative treatment effect. Missing analysis details and unreported outcome results further constrain interpretation.

14. Why This Trial Matters Statistically

This study is statistically notable because its registry record makes the endpoint and analysis population identifiable while leaving the primary numerical result unavailable. Readers can determine that investigator satisfaction at 6 months was assessed on a scale anchored from very dissatisfied to very satisfied, and that the analysis population included 134 subjects and 205 breasts. They cannot assess the outcome’s mean, spread, or precision because those results are not reported in the registry record.

The difference between participant counts and breast counts also matters. A participant may contribute more than one breast, so the data structure can include observations that are related within a person. General statistical principle: methods should account for dependence when multiple observations from one participant contribute to an analysis. The registry does not explain the unit used for the satisfaction assessment or whether such dependence was addressed. This is an important reporting gap, not evidence that the analysis was necessarily conducted incorrectly.

The single-group design gives the study a descriptive focus. It can document experience among recipients, but it does not supply a like-for-like control comparison. This distinction prevents a descriptive rating or safety count from being interpreted as a comparative effect. The record also identifies multiple outcome measures without reporting an analysis plan or multiplicity procedure, leaving the approach to several possible outcome assessments unclear.

More complete reporting of the primary estimate, its uncertainty, the analysis unit, missing-data handling, and statistical methods would allow more rigorous evaluation. The present record still has value in defining the study question and population, but its omissions limit what can be learned about the measured outcome and how it was analyzed.

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 limitation for interpreting the primary outcome is that its numerical result is not reported in the registry record. The record states the scale, time point, summary measure, and analysis population, but does not give a mean, standard deviation, or confidence interval. Thus, neither the level of investigator satisfaction nor its precision can be evaluated.

The single-group design has no like-for-like comparator, and allocation is listed as NA. Consequently, the study cannot provide a direct comparison with another intervention from the design described in the registry. Its findings, if reported, would be descriptive of the implanted group rather than a randomized treatment contrast.

The analysis population includes both people and breasts, but the registry does not state the unit used for the primary rating or how any within-participant dependence was handled. The record also does not describe the statistical analysis plan, the methods used for missing data, or any adjustment for multiple outcomes. These details are not reported in the registry record.

Although the registry states that four participants discontinued and one missed the 6-month visit, it does not give the reasons or explain how those missing observations were treated. The reported serious-event percentages also lack denominator details in the information available for interpretation, and the death count is not reported in the registry record. These limitations constrain both outcome and safety interpretation without establishing that unreported methods or results were absent from all study materials.

16. Related Tutorials

17. Related Statistical Calculators

18. Sources

• ClinicalTrials.gov: The SERI® Surgical Scaffold Use in Reconstruction Post Market Study for Tissue Support and Repair in Breast Reconstruction Surgery — NCT01256502.
• Registry record last updated 2017-11-06; status last verified 2017-10.
• Results first posted 2014-05-16.
• 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 completed SERI® Surgical Scaffold post-market study concerned breast reconstruction and was registered as a single-group device study. Enrollment was 160; the registry lists 139 participants and 214 breasts implanted during Stage I reconstruction, with 134 subjects and 205 breasts in the primary analysis population. The primary outcome was investigator satisfaction at 6 months on an 11-point scale, summarized as a mean and standard deviation, but its numerical result is not reported in the registry record.

The registry lists two secondary outcomes, no registered analyses, and no separate comparator group. It reports serious adverse events affecting 25 of 139 participants and other adverse events affecting 107 of 139 participants. A death count is not reported in the registry record. Missing-data methods, statistical analysis details, and the numerical primary result are also not reported in the registry record.