Vaginal Cuff Dehiscence and Thermal Injury During TLH: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Vaginal Cuff Dehiscence and Thermal Injury During TLH (NCT02080546), a randomized na study. The primary outcome is Degree of Thermal Injury at the Time of Laparoscopic Hysterectomy.

2. Clinical Question

3. Trial Design

The registry describes a randomized, parallel-group study with no masking. Participants scheduled for TLH were to be randomized to colpotomy incision with V-mode or with standard cut/coag electrothermal energy. The registry lists an enrollment of 120 and marks the study completed. It identifies Duke University as the sponsor. The recorded start is 2009-12 and the primary completion is 2014-02.

The primary outcome is titled degree of thermal injury at the time of laparoscopic hysterectomy. Its measure is the distance, in millimeters, over which thermal tissue injury extends. The outcome record says it was assessed at the anterior margin in 91 specimens and at the posterior margin in 93 specimens. The participant counts associated with the two arms are 49 for cut/coag and 52 for V-mode. These participant counts and specimen counts describe different units; the record does not provide further details about how multiple specimens relate to participants.

The brief description says the randomized comparison would compare depth of thermal injury between the two groups and use a chi-square test to assess differences in clinical outcomes. It also describes a retrospective component concerning prevalence of vaginal cuff injury and cross-tabulations of dehiscence with proposed risk factors. The available registry information does not report results for that retrospective component, nor does it explain how it relates to the randomized comparison. Further details of randomization procedures, allocation concealment, the analysis population, and trial conduct are not reported in the registry record.

The listed timeframe for the primary outcome is up to 36 months. The record does not explain how this timeframe applies to measurement of tissue injury at surgery or to the clinical healing outcomes. It lists incidence of clinical surrogates of compromised vaginal cuff healing as a secondary outcome, without numerical results or a detailed definition of the surrogates.

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: 19 subjects either withdrew or were excluded from the study. Thermal injury could not be assessed in 18 specimens because of sampling error.

Overall Study

Analysis population for the primary outcome, as defined in the registry: 49 participants were included in the cut/coag arm and 52 participants in the V mode arm. Thermal injury was assessed at the anterior margin in 91 specimens and at the posterior margin in 93 specimens.

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 Degree of Thermal Injury at the Time of Laparoscopic Hysterectomy, measured over up to 36 months.

The primary endpoint is the degree of thermal injury at the time of laparoscopic hysterectomy. It is defined as the distance in millimeters over which thermal tissue injury extends. This is a continuous measurement: larger recorded distances would represent injury extending farther through tissue, while smaller distances would represent a shorter measured extent. That description explains the endpoint’s scale, but the registry record does not report the observed measurements or their summary by treatment arm.

Measuring tissue injury offers a direct way to compare the local tissue effect associated with the two electrothermal incision modes. The study’s rationale connects thermal injury with possible compromise in vaginal cuff healing, while also listing clinical surrogates of compromised healing as a secondary outcome. A tissue measurement and a clinical healing outcome are not interchangeable: the former describes measured injury, whereas the latter concerns clinical events or signs. The registry record does not report evidence establishing how closely the measured depth predicts the clinical outcomes.

The endpoint was assessed at anterior and posterior specimen margins. The registry gives counts of 91 anterior-margin specimens and 93 posterior-margin specimens, but does not state whether the analysis treated those measurements as independent, paired within participants, or combined in another way. The outcome’s listed unit is millimeters, its parameter is mean, and its dispersion is full range. Numerical means and ranges are not reported in the registry record, so the magnitude and precision of the observed injury in either arm cannot be described.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The registry describes a randomized parallel-group comparison without masking. Randomization is a design method intended to allocate participants to treatment groups by chance, reducing the opportunity for systematic differences in measured and unmeasured characteristics at assignment. It does not guarantee that groups will be identical, and it does not resolve questions about adherence, missing measurements, outcome assessment, or how observations were analyzed. The record does not report the sequence-generation method, allocation concealment, or details of implementation.

What does the primary outcome measure?

The outcome is the distance in millimeters over which thermal tissue injury extends. The listed summary measure is the mean, with full range as the dispersion measure. A mean describes the arithmetic average of observed measurements; a range describes the span from the smallest to the largest observed value. These summaries answer different questions: the mean indicates the average measured extent, while the range conveys the observed spread at the extremes. Neither summary is available by arm in the registry record, so neither the average nor the spread can be interpreted for this trial.

The outcome was assessed at anterior and posterior margins. General statistical consideration: when a participant contributes more than one measurement, those measurements may be correlated rather than independent. Treating correlated measurements as if they came from unrelated participants can make uncertainty estimates misleading. The registry record does not say whether multiple margins came from the same participant, how such measurements were handled, or whether the analysis was conducted at the participant or specimen level.

How should a group comparison be interpreted?

A comparison of group means would describe the average difference in measured injury between assigned incision modes, if the analysis and results were reported. A confidence interval is a range of values compatible with the data under the specified statistical model; it communicates uncertainty about an estimate, rather than proving that a particular value is true. A p-value, when reported, measures how incompatible the observed data are with a specified null hypothesis under the assumptions of the test. It does not measure the size or clinical importance of an effect. The registry record provides no primary-outcome estimate, confidence interval, or p-value.

The brief description says depth of thermal injury would be compared between groups. It does not identify a specific model for the primary outcome or report assumptions, covariate adjustment, or handling of multiple specimen measurements. Those details are not reported in the registry record and should not be inferred from the outcome’s mean summary measure.

What does the stated chi-square test address?

The study description says a chi-square test would be used to test for a difference in clinical outcomes between the two groups. General explanation: a chi-square test can assess whether categorical outcome counts differ across groups, subject to assumptions about the data and expected cell counts. It does not directly estimate a continuous mean difference, so it is distinct from the stated comparison of injury depth. The registry record does not give the clinical outcome counts, test statistic, degrees of freedom, p-value, effect estimate, or confidence interval. The exact categorical outcomes included in that test are also not defined in the posted information.

What can planning calculations say?

The record describes planning illustrations based on the observed effect, with a two-sided significance level of 0.05, equal allocation, and a normal approximation. It says that the effect to detect is a stated fraction of the observed effect. Such calculations are prospective planning illustrations, not evidence about what the trial found and not observed power. They do not establish the trial’s original design or sample-size justification. The record explicitly distinguishes those illustrations from the trial’s own design. No actual planning outputs or sample-size justification are reported in the registry record.

General explanation: planning calculations depend on assumptions about the target effect, variability, significance threshold, allocation, and analysis. If an observed effect is used as an input after a study, a resulting planning illustration is conditional on that observed estimate and may be unstable when the estimate is imprecise. It should not be treated as an independent confirmation of the result. Because numerical outcome estimates and planning outputs are not reported in the registry record, no trial-specific planning conclusion can be drawn.

What is not specified?

The registry does not report the analysis population, how missing measurements were handled, whether any interim analyses occurred, whether adjustments were made for multiple outcomes or comparisons, or whether any covariates were included. It also does not report a prespecified statistical analysis plan. These omissions matter because analysis choices can affect estimates and their uncertainty. Without those details and the outcome results, the statistical evidence cannot be reconstructed or independently evaluated from the registry record.

10. Multiplicity, Missing Data and Analysis Populations

The record lists a primary endpoint of thermal injury and a secondary outcome concerning clinical surrogates of compromised vaginal cuff healing. The brief description also mentions a retrospective component examining prevalence of vaginal cuff injury and associations between dehiscence and proposed risk factors. The registry record does not explain whether these components were analyzed together, whether they had separate analysis plans, or how many statistical comparisons were conducted.

Multiplicity arises when several outcomes, groups, time points, or statistical tests are considered. General explanation: testing many hypotheses can increase the chance that at least one result appears notable by chance. Methods to address multiplicity may include defining a primary comparison in advance or adjusting inference across tests. Whether any such approach was used is not reported in the registry record. The presence of a named primary endpoint does not by itself establish how secondary or retrospective analyses were handled.

Missing-data methods and analysis populations are not reported in the registry record. The primary outcome description gives 49 participants in the cut/coag arm and 52 in the V-mode arm, while reporting specimen counts separately for anterior and posterior margins. The record does not say whether these counts reflect all randomized participants, all participants with outcome measurements, or another analysis set. It also does not describe missing specimens, exclusions, withdrawals, or reasons for unavailable measurements.

Without these details, it is not possible to assess whether missing measurements could have affected the comparison or whether the reported counts correspond to an intention-to-treat analysis. Interim analyses, stopping rules, and any adjustment for repeated testing are likewise not reported in the registry record. These are limits on interpretation, not evidence that any particular method was or was not used.

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.

The registry lists zero serious adverse events and zero other adverse events for the cut/coag arm, with 49 participants at risk in each category. For the V-mode arm, it lists zero serious adverse events and zero other adverse events, with 52 participants at risk in each category. These are the adverse-event figures posted for the two arms.

A recorded zero means that no events in the listed category are reported for that group in the registry entry. It should not be read as proof that no adverse events of any kind occurred, or that all possible events were captured. The record does not describe the adverse-event collection period, definitions, monitoring procedures, or completeness of reporting. Deaths are not reported in the registry record; the death fields are not populated with event counts.

The listed at-risk counts should be read as the denominators accompanying the adverse-event categories, not as evidence about the duration or completeness of follow-up. The registry’s primary outcome timeframe is stated as up to 36 months, but the safety information does not specify its own follow-up window. These entries therefore allow a narrow description of posted serious and other adverse-event counts, but not a broader assessment of comparative safety.

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

The registry record establishes that the study was designed as a randomized comparison of V-mode and cut/coag electrothermal colpotomy incision during TLH, with thermal injury depth named as the primary endpoint. It also identifies clinical surrogates of compromised vaginal cuff healing as a secondary outcome. Those details describe the research question and design, not the direction or size of any treatment effect.

The record does not report the arm-specific injury measurements or a statistical comparison. It therefore does not show whether thermal injury was greater in one arm, whether the groups were similar, or how precisely any difference was estimated. It also does not provide results for the clinical healing outcome. The listed zero adverse-event counts are limited to the recorded serious and other adverse-event categories and do not answer the primary efficacy or injury question.

Randomization is relevant because it is intended to make a fair comparison between assigned groups. But design features cannot replace outcome data. Without the results and key analysis details, readers cannot judge the observed effect, its uncertainty, the relevance of any difference, or the impact of missing measurements and specimen-level clustering.

The registry record also does not establish that a tissue-injury measurement predicts a clinical healing outcome. The study’s stated rationale connects these topics, but the strength of that relationship would require reported results and a suitable analysis. A surrogate outcome should not automatically be interpreted as a clinical outcome.

Accordingly, the defensible conclusion is limited: the record describes a randomized study and its intended comparison, but the posted information does not permit an evidence-based conclusion about the comparative outcome. Absence of reported results should not be mistaken for evidence of no difference, and it should not be taken as evidence that one mode is superior or inferior.

13. Why This Trial Matters Statistically

This trial raises a useful statistical distinction between a biological measurement and a clinical outcome. Depth of thermal injury is recorded as a distance in millimeters, while compromised healing is described through clinical surrogates. A study can examine both, but each requires a clear definition and an analysis appropriate to its measurement scale. The registry names both types of outcomes, yet does not post their results or provide enough detail to assess their relationship.

The specimen-based measurement also highlights the importance of identifying the unit of analysis. Measurements at anterior and posterior margins may not represent independent observations if multiple specimens or margins come from one participant. General statistical principle: analysis should account for the way observations are grouped or repeated when that structure creates correlation. The record’s separate participant and specimen counts make that issue relevant, but do not explain how it was handled.

Randomization and masking are separate design features. The study is listed as randomized and unmasked. Randomization supports a structured group comparison, while lack of masking may matter for outcomes involving judgment or ascertainment. The registry does not describe how the tissue measurement or clinical surrogates were assessed, so the possible influence of outcome assessment cannot be evaluated.

Finally, the record illustrates why planned methods and posted results must be distinguished. It describes a comparison of injury depth and a chi-square test for clinical outcomes, but gives no outputs from those analyses. A stated test cannot establish a result, and a planning illustration based on an observed effect is not a substitute for the original design rationale or an uncertainty estimate. Statistical interpretation depends on transparent reporting of estimates, variability, analysis populations, and missing-data handling; those details are not reported in the registry record.

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 principal limitation for interpretation is that numerical primary-outcome results are not reported in the registry record. There are no arm-specific means, ranges, between-arm estimates, confidence intervals, or test results. The same is true of the listed clinical healing outcome: the registry does not give event counts, definitions detailed enough to identify each surrogate, or inferential results.

The record reports participant counts by arm and specimen counts by margin, but does not explain the relationship between these observations. It is not clear whether each participant contributed one or more specimens or how anterior and posterior measurements were combined or modeled. That information is necessary to understand the effective analysis unit and the uncertainty around any comparison.

Additional design and analysis details are absent. The registry does not report eligibility criteria beyond women already scheduled for TLH, baseline characteristics, the randomization procedure, allocation concealment, adherence, exclusions, the analysis population, or missing-data handling. It does not report an analysis plan, sample-size justification, interim analyses, or methods for addressing multiple comparisons. The planning illustrations described in the record are explicitly not the trial’s own design calculations.

The adverse-event entries show zero serious and zero other adverse events in both arms, but the record does not describe ascertainment, follow-up duration for safety, or reporting completeness. Deaths are not reported in the registry record. The listed primary outcome timeframe of up to 36 months is not explained in relation to a measurement made at surgery, and the clinical outcome timeframe is not detailed.

These limitations do not establish that the study was poorly conducted; they indicate what cannot be assessed from the registry information. In particular, the absent outcome results prevent an evaluation of effect direction, magnitude, and precision.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Vaginal Cuff Dehiscence and Thermal Injury During TLH — NCT02080546.
• Registry record last updated 2016-06-03; status last verified 2016-01.
• Results first posted 2016-06-03.
• 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

NCT02080546 is a completed, randomized, parallel-group, unmasked study sponsored by Duke University. It lists enrollment of 120 and compares V-mode with standard cut/coag electrothermal energy for colpotomy incision during TLH. The primary outcome is the distance in millimeters over which thermal tissue injury extends, summarized as a mean with full range. The record reports 49 participants in the cut/coag arm and 52 in the V-mode arm, with assessments at anterior and posterior specimen margins.

The brief description also identifies clinical surrogates of compromised vaginal cuff healing and describes a chi-square test for clinical outcomes. Numerical primary and secondary outcome results, statistical test results, missing-data methods, analysis populations, and a detailed analysis plan are not reported in the registry record. Serious and other adverse-event counts are listed as zero in both arms; deaths are not reported in the registry record. The posted information supports description of the study design and outcomes, but not a conclusion about comparative effects.