Ultravision Visual Clearing System in Laparoscopic Hysterectomy and Myomectomy: Complete Statistical Analysis

1. Trial at a Glance

This page covers the registry results for Ultravision Visual Clearing System in Laparoscopic Hysterectomy and Myomectomy (NCT03634306), a randomized na study. The primary outcome is Quality of Surgical Field Visualization.

2. Clinical Question

3. Trial Design

The registry describes a prospective, randomized, controlled study with a parallel design and single masking. The study has three arms: laparoscopic hysterectomy with Ultravision, laparoscopic hysterectomy without Ultravision per standard of care, and laparoscopic myomectomy with Ultravision. The record lists an enrollment of 35. The arm descriptions list 15 participants in each hysterectomy group and five in the myomectomy group. No randomized myomectomy comparison is described.

The brief summary says that hysterectomy participants were randomized between Ultravision and no Ultravision. It also describes the investigator as blinded during the procedure through patient discharge: the system was present in both hysterectomy groups, its generator was covered, and it was on or off according to randomization. The identity of any other masked parties is not reported in the registry record. The registered masking classification is single.

The trial is marked completed. Its recorded start date is 2018-10-11, and its primary completion date is 2018-12-21. The phase is listed as NA. These registry entries describe the design and administrative status, but do not supply a statistical analysis plan or the results needed to assess the primary randomized comparison.

The study objectives also include procedural characteristics and clinical outcomes. Secondary outcomes listed in the record include operative procedure disruption, intra-abdominal pressure, pressure adjustments and their duration, and temperature measurements at specified times. The registry lists 26 outcome measures but lists no analyses. Definitions, results, and analysis populations for those measures 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.

Overall Study

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 Quality of Surgical Field Visualization, measured over End of procedure.

The primary endpoint is titled Quality of Surgical Field Visualization. It is described as a participant measure of visualization in the laparoscopic field of view at the end of the procedure, assessed with a Visual Analog Scale. The record assigns 0 to imperceptible visible interference, 2-3 to perceptible-to-interfering, 4 to interfering, and 5 to highly interfering. Although the measure is called a 5 point scale, the description does not explain the value 1 or how responses were converted into the registered endpoint, which is listed as a number of participants.

Visualization is a relevant procedural outcome because visibility is a direct feature of the operating field that the device is intended to address. That rationale does not itself demonstrate a clinical benefit. A subjective or rated endpoint also needs a clear scoring and summary method for readers to interpret a group comparison. The registry record does not report the scoring instructions beyond the stated anchors, assessor details beyond the masking description, or a summary measure for the comparison.

No numerical primary endpoint results, group-level score distributions, effect estimate, or confidence interval are reported in the registry record. The record also indicates that the primary outcome has several categories or time points and is not reduced to one comparison. Without a reported endpoint result and its analysis, the direction, size, and precision of any hysterectomy-group difference cannot be assessed from the registry record.

7. Why No Re-analysis Is Shown

8. Statistical Interpretation

9. Statistical Methods Explained

The methods that can be described from the registry record are limited to its design classifications, intervention descriptions, outcome definitions, and the stated assumptions for planning illustrations. The record says the trial was randomized, parallel, and single-masked. It does not report the statistical analysis plan, the method used to generate or conceal the allocation sequence, or the statistical tests used for the outcomes. These omissions matter because design labels do not specify how the collected measurements were analyzed.

What does randomization contribute?

In general, randomization assigns participants to comparison groups by chance. When implemented appropriately, it can reduce systematic differences between groups at the start of a study, including differences that are not measured. It does not guarantee that all groups will be identical, particularly in a small study, and it does not remove uncertainty in estimates. Here, the record identifies randomization for the hysterectomy comparison. It does not report the allocation procedure or baseline characteristics, so those details cannot be evaluated from the registry record.

The parallel design means the listed groups are separate arms rather than successive treatment periods for the same participant. The brief summary says the hysterectomy comparison involved Ultravision switched on or off with the generator covered, and describes investigator blinding during the procedure through discharge. Blinding can reduce the chance that knowledge of assignment influences care or assessment, depending on who is masked and how outcomes are measured. The record does not report additional masking details or whether the visual assessment was made by a masked assessor.

How should the primary measure be understood?

The primary measure is a rating of visualization at the end of the procedure. In general, a scale-based outcome needs an explicit scoring rule and a defined summary, such as a distribution of scores or a prespecified category. The registry gives several verbal anchors but does not explain the value 1, identify a threshold for classifying a participant, or state how scores were summarized. It registers the measure as a number of participants, which does not by itself clarify whether the analysis concerned individual scale values, grouped categories, or another representation.

For a randomized comparison, an effect estimate would describe the contrast between the hysterectomy groups using the chosen endpoint summary. A confidence interval, in general, describes the range of values compatible with the data and statistical model at a stated confidence level. It communicates precision as well as direction and magnitude. No primary effect estimate or confidence interval is reported in the registry record, so precision cannot be assessed. Nor is there a reported test statistic or p-value for the primary outcome.

What can be inferred from the planning assumptions?

The stated sample-size assumptions specify a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. In general, a significance level is a decision threshold used in a statistical testing procedure; it is not the probability that a particular conclusion is correct. A normal approximation uses a normal distribution to approximate the sampling behavior of an estimate under stated conditions. Its suitability depends on the outcome, sample size, and analysis, but the registry does not identify the precise endpoint model used for any calculation.

The assumptions describe illustrations based on fractions of an observed effect, not the original trial’s design justification. Planning illustrations ask what sample size might be needed under specified assumptions. They do not report the study’s observed power, and a planning calculation cannot replace the observed treatment contrast and its uncertainty. The record does not provide the original sample-size justification, nor does it report the numerical endpoint result needed to judge the observed effect from the primary outcome.

For event outcomes, a general analysis might compare participant counts or event rates between arms. The choice depends on whether the outcome is a participant with any event, a count of multiple events, or a rate over time. The safety record reports participants affected and participants at risk for serious and other events, but does not explain event definitions, recurrent-event handling, follow-up completeness, or any model. The registry’s event counts therefore support a descriptive reading only.

Over-dispersion is a general concern for count data when observed variability exceeds what a simple count model expects. It can make standard errors too small if ignored. The record does not report a count model or evidence about over-dispersion, so no claim can be made about whether it was assessed or relevant to a particular analysis. Similarly, the listed pressure and temperature outcomes may require methods suited to repeated measurements or continuous data, but the registry record does not specify their analysis methods. Those are general methodological considerations, not descriptions of an analysis performed in this trial.

What does the analysis listing establish?

The record lists 26 outcome measures and zero analyses. This means the registry record does not list outcome analyses. It should not be interpreted as proof that investigators conducted no analyses outside the registry. It does mean that readers cannot use the record to verify the statistical methods, reproduce estimates, evaluate multiplicity adjustments, or compare planned analyses with reported results. No recalculated estimates are available from the posted summaries, and the record does not identify a sponsor analysis to compare against an independent recalculation.

10. Multiplicity, Missing Data and Analysis Populations

The registry lists 26 outcome measures, spanning the primary visualization outcome and secondary measures such as procedure disruption, intra-abdominal pressure, pressure adjustments, and temperature at specified times. Considering multiple outcomes or time points creates a multiplicity issue: in general, the chance of at least one apparently unusual result can increase when many statistical tests are conducted. Researchers may address this through a prespecified hierarchy, adjusted testing, or a clear distinction between confirmatory and exploratory analyses. Which approach, if any, was used is not reported in the registry record.

The record lists zero analyses. It does not give a statistical analysis plan, identify a family of outcomes for multiplicity control, describe any adjustment, or report p-values. Therefore, no conclusion about how multiplicity was handled can be drawn. Nor can readers distinguish prespecified analyses from additional analyses using the registry record alone.

Missing-data handling is also not reported in the registry record. There is no accounting of missing primary endpoint measurements, exclusions after randomization, withdrawals, or the method used to handle incomplete measurements. The registry’s enrollment and arm-level safety counts do not establish that every participant contributed to every endpoint. The analysis population—such as all randomized participants or only those with an observed outcome—is not identified.

These omissions affect interpretation, not just reporting detail. Missing outcomes can reduce precision, and if missingness is related to participant characteristics or outcomes, it can also bias a comparison. General methods include analyzing available observations under stated assumptions, imputing missing values, or conducting sensitivity analyses; none is documented in the registry record. Without denominators and analysis populations for the primary endpoint, it is not possible to assess completeness or determine whether the reported groups remained comparable for that analysis.

11. Safety Results

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

Deaths

Other (non-serious) adverse events

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

Most frequent non-serious adverse event terms

The serious adverse event counts are zero for ARM 1 among 15 participants at risk, zero for ARM 2 among 15 participants at risk, and zero for ARM 3 among five participants at risk. The record also lists zero deaths in each arm. These are descriptive counts as registered; they do not establish that the possibility of serious adverse events has been ruled out.

The record separately reports other adverse events: five participants affected among 15 at risk in ARM 1, nine among 15 in ARM 2, and zero among five in ARM 3. These are not serious adverse event counts, and they should not be substituted for them. The registry record does not provide further event terms in the serious event listing or explain the definitions and ascertainment procedures used for serious and other events.

Safety counts require context about the events collected, follow-up period, completeness, and whether participants could experience more than one event. Those details are not reported in the registry record. The myomectomy arm also differs in procedure and lacks a listed control arm, so its counts do not furnish a randomized safety comparison. The figures are best read as the events recorded in each listed group, without deriving a comparative risk or concluding that one approach is safer.

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

This trial record identifies a randomized comparison of laparoscopic hysterectomy with Ultravision versus hysterectomy without the system, and a separate arm in which myomectomy was performed with Ultravision. Its stated primary question concerns visualization at the end of the procedure. Those design features indicate what the study set out to evaluate, but they are not themselves evidence of an outcome difference.

The registry does not report primary endpoint results, a group contrast, an uncertainty interval, or a statistical test. It therefore does not show the direction or size of any difference in visualization, nor how precisely such a difference was estimated. No conclusion about the clinical effect of the system follows from the absence of a posted primary result. A missing result is not equivalent to a finding of no difference.

The myomectomy arm cannot answer the same causal question as the randomized hysterectomy arms because the record does not list a myomectomy control. Results from that arm, even if fully reported, would describe outcomes under Ultravision in that group rather than isolate the effect of the system for myomectomy.

The safety figures record no serious adverse events and no deaths in the listed arms, alongside separate counts for other adverse events. Such counts are limited by their definitions, follow-up, and completeness, which are not detailed in the record. They should not be interpreted as proof that serious harms are impossible or as a definitive between-group safety comparison.

Finally, the listed planning assumptions do not establish observed power or supply the missing endpoint estimate. A sample-size illustration is conditional on its assumptions; it cannot replace results from the randomized comparison. The appropriate statistical reading is therefore bounded: the design and intended question are documented, but the registry record does not provide enough outcome analysis to judge the primary effect or its uncertainty.

13. Why This Trial Matters Statistically

This study illustrates a central distinction in clinical trial interpretation: a randomized design can be informative in principle, while a registry record without endpoint analyses cannot answer the comparative question. Randomization is a strength of the stated hysterectomy design because it is intended to reduce systematic allocation differences. But a design description does not provide an estimated contrast, and it does not show whether the planned outcome was measured and analyzed as intended.

The trial also makes clear why the comparison must be defined carefully. The randomized arms concern hysterectomy, while the myomectomy arm has no listed comparator. Keeping these questions separate avoids treating an uncontrolled procedural group as if it were part of a randomized treatment contrast. Procedure type is part of the context for interpreting the arm descriptions and outcome measures.

The endpoint highlights the importance of operational definitions. A scale with verbal anchors needs a clear account of scoring, categories, and analysis if readers are to understand an effect estimate. Here, the primary outcome description does not explain every scale value or the summary represented by the registered participant-count measure. This limits interpretation even before considering statistical uncertainty.

Finally, the record lists many outcome measures but no analyses. Multiplicity, missing data, analysis populations, and uncertainty are not optional details when drawing conclusions from trial results. Their absence prevents readers from evaluating the robustness and precision of the findings. The safety counts offer descriptive information, but they do not overcome the missing primary comparison. Statistically, the main lesson is to separate what the design intended to estimate from what the posted results actually allow readers to conclude.

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 registry record does not report the numerical results for the primary visualization endpoint, so no effect estimate or precision assessment is possible. The primary measure is described as a Visual Analog Scale but also registered as a number of participants; the description does not explain the value 1 or specify how scores were summarized. These gaps leave uncertainty about the exact endpoint analysis.

Although the study is identified as randomized, the allocation sequence, concealment procedures, baseline characteristics, and analysis population are not reported. The record describes investigator blinding during the procedure through discharge, but does not identify other masked parties or explain how endpoint ratings were protected from knowledge of assignment. The handling of missing observations and post-randomization exclusions is also not reported in the registry record.

The myomectomy arm has no listed comparator, limiting it to a descriptive role for comparative interpretation. The record lists 26 outcome measures but no analyses, and does not provide a statistical analysis plan or explain multiplicity handling. Consequently, selective reporting, analysis choices, and the relationship between planned and reported outcomes cannot be evaluated from the registry record.

Safety interpretation is constrained by absent definitions and details about event ascertainment and follow-up. Zero serious events in the listed groups is a descriptive observation, not evidence that uncommon events cannot occur. The registry record also does not report a trial-specific sample-size justification. The stated planning assumptions are illustrations, not a substitute for the missing outcome estimates or a measure of observed power.

15. Related Tutorials

16. Related Statistical Calculators

17. Sources

• ClinicalTrials.gov: Ultravision Visual Clearing System in Laparoscopic Hysterectomy and Myomectomy — NCT03634306.
• Registry record last updated 2020-03-10; status last verified 2019-01.
• Results first posted 2020-01-29.
• 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

NCT03634306 is a completed, randomized, parallel study of the Ultravision Visual Clearing System in laparoscopic hysterectomy and myomectomy. The registry describes a single-masked design and lists an enrollment of 35. Its hysterectomy arms compare Ultravision with standard-of-care hysterectomy without the system; a separate myomectomy arm uses Ultravision without a listed comparator.

The primary outcome is quality of surgical field visualization at the end of the procedure, measured with a Visual Analog Scale. The registry record does not report a numerical primary result or statistical analysis. It lists 26 outcome measures and zero analyses. Serious adverse event counts and death counts are zero in each listed arm; other adverse events are reported separately. The recorded study start date is 2018-10-11 and the primary completion date is 2018-12-21. The available record describes the study’s question and design, but does not establish the primary comparative effect or its precision.