This page provides an independent statistical analysis and educational interpretation of publicly reported results. ClinicalTrials.gov provides the official trial registry record. Numerical trial results on this page are restricted to the results posted in the ClinicalTrials.gov record; calculations added by Clinical Biostats are labelled as such.
1. Trial at a Glance
This page covers the registry results for Safety and Feasibility of the Use of the Dual Robotic Arm Accessory With the Levita Magnetic Surgical System in Laparoscopic Procedures (NCT05695989), a na na study. The primary outcome is Adverse Events- Safety.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT05695989 |
| Phase | NA |
| Condition | Bariatric Surgery Candidate, Cholelithiases, Other Disease |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 22 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Levita Magnetics |
| Results posted | Yes |
2. Clinical Question
Population
The study enrolled candidates for bariatric surgery, people with cholelithiases, and people with other diseases who underwent laparoscopic procedures. The registry lists 22 participants as enrolled. The adverse-event summary uses a denominator of 20, and the reason for that difference is not reported in the registry record.
Intervention
The intervention was the Dual Robotic Arm Accessory (DRAA) used with the Levita Magnetic Surgical System (MSS). The registry describes the accessory as a robotic platform intended to assist external management of the controlling magnet and laparoscopic camera, giving the surgeon control of surgical tools.
Comparator
There was no comparison group. The study is described as prospective, multicenter, single-arm, and open label. Its findings therefore describe participants in the DRAA group; they do not provide a like-for-like comparison with another device, procedure, or usual-care group.
Primary question
The primary endpoint concerns device-related adverse events over 30 days. The study also lists outcomes for whether the accessory could engage, move, and decouple with the magnetic system as controlled by the surgeon, and for conversion to open surgery. The registry record does not give numerical results for those secondary outcomes.
In statistical terms, the study asks whether use of the combined system can be assessed for safety and feasibility in the enrolled surgical setting. It is not designed as a randomized test of whether the accessory performs better than an alternative. Without a control group, the observed event counts cannot isolate the accessory’s contribution from other features of the operation, participants’ underlying conditions, or other aspects of care. The record supplies a descriptive safety summary, but it does not report a detailed result for the primary endpoint or the listed feasibility outcomes.
3. Trial Design
The registry describes a prospective, multicenter, single-arm, open-label study of the Dual Robotic Arm Accessory used with the Levita Magnetic Surgical System in laparoscopic procedures. Enrollment was 22. The listed conditions are bariatric surgery candidate, cholelithiases, and other disease. The intervention is classified as a device, and the study phase is listed as not applicable.
Prospective means that the study was set up to follow participants forward for the stated assessment, rather than relying only on a retrospective review. Multicenter indicates that more than one center was involved, although the number and identities of centers are not reported in the registry record. Open label means the study is not described as masked. The allocation field is listed as not applicable, consistent with the single-group design rather than assignment between trial arms.
The study began on 2023-01-19, had a primary completion date of 2023-03-08, and is listed as completed. The primary endpoint is adverse events related to the device, assessed over 30 days. Listed secondary outcomes are the rate at which the DRAA is able to engage, move, and decouple with the magnetic system under surgeon control, and the conversion rate to open surgery. The registry does not give numerical results for those secondary outcomes.
Because there is only one group, the design supports description of outcomes among participants treated with the system but not a controlled estimate of how outcomes would differ under another approach. The registry record does not report the eligibility criteria in detail, the number of sites, a protocol-based sample-size justification, or a detailed statistical analysis plan. Those omissions limit assessment of how the enrolled participants and reported measures relate to the study’s intended conclusions.
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
| Stage | DRAA (Dual Robotic Arm Accessory) |
|---|---|
| STARTED | 22 |
| COMPLETED | 20 |
| NOT COMPLETED | 2 |
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.
| Characteristic | Unit | DRAA (Dual Robotic Arm Accessory) |
|---|---|---|
| Participants analysed | 20 | |
| Age, Categorical: <=18 years | Participants | 0 |
| Age, Categorical: Between 18 and 65 years | Participants | 18 |
| Age, Categorical: >=65 years | Participants | 2 |
| Sex: Female, Male: Female | Participants | 10 |
| Sex: Female, Male: Male | Participants | 10 |
| Ethnicity (NIH/OMB): Hispanic or Latino | Participants | 20 |
| Ethnicity (NIH/OMB): Not Hispanic or Latino | Participants | 0 |
| Ethnicity (NIH/OMB): Unknown or Not Reported | Participants | 0 |
| Region of Enrollment: Chile | participants | 20 |
6. Primary Endpoint
The registry lists the primary outcome as Adverse Events- Safety, measured over 30 days.
| Element | Registry entry |
|---|---|
| Result type | Number |
| Measure of spread | not applicable |
| Unit | Device related adverse events |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is titled “Adverse Events- Safety.” Its stated unit is device-related adverse events, its parameter is a number, and its timeframe is 30 days. This endpoint is intended to capture adverse events related to the device during the specified follow-up period. Counting events or participants affected can provide a direct descriptive account of observed safety issues in a study group.
For a device feasibility study, safety monitoring is important alongside whether the device can be used as intended. However, the registry record does not provide a separate numerical primary-outcome result with a detailed definition of which events qualify, how relatedness was assessed, or whether the reported measure counts events or participants with events. The adverse-event summary lists participants affected by serious and other adverse events, but does not establish that every event in those categories was device-related. The listed safety figures should therefore be read as the registry’s adverse-event summary, not as a fully specified estimate of the primary endpoint.
The timeframe also matters: the endpoint description refers to 30 days. It does not, by itself, describe safety beyond that period. The registry record does not report further detail about event timing or follow-up completeness.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry’s adverse-event summary lists 20 participants at risk in the DRAA group. Among them, 0 were affected by serious adverse events and 12 were affected by other adverse events. These are descriptive counts for the group, not a comparison between treatments. The enrollment entry is 22, while the adverse-event summary denominator is 20; the reason for the difference is not reported in the registry record.
The serious-event count is an observed count, not proof that serious events cannot occur. In a study with a limited number of participants, an event that was not observed may still be compatible with a range of underlying risks. A confidence interval, if reported, would express uncertainty around an estimate; no confidence interval for these safety figures is reported in the registry record. The figures also do not establish that the accessory caused or prevented an event.
The 12 participants affected by other adverse events should not be interpreted as 12 device-related events. The summary groups participants by adverse-event seriousness and identifies the DRAA group, while the primary endpoint is described as device-related adverse events. The registry record does not give event terms or a detailed attribution breakdown. It also does not report how many events occurred per affected participant. A participant count and an event count are different measures: one person can experience more than one event, but the record does not say whether that happened.
No numerical results are listed for the secondary feasibility outcome or conversion to open surgery. The record therefore does not allow a statistical assessment of those outcomes. Nor does it report a comparator group, so there is no basis for estimating a between-group effect or separating the observed outcomes from the background risks of laparoscopic procedures and participants’ conditions.
There are no analyses listed in the registry record. No inferential test, adjusted estimate, or uncertainty interval is reported. The reader can describe the posted adverse-event counts, while recognizing that the denominator differs from enrollment and that the available detail does not fully define the primary endpoint result. Interpretation should remain limited to these observed summaries and the stated follow-up period.
9. Statistical Methods Explained
Statistical methods are useful only when they match the design and the question being asked. This study is described as single-group and open label, with no randomized comparison. Its posted safety information is therefore most naturally read descriptively: how many participants were listed at risk and how many were affected in each reported adverse-event category. The registry lists no analyses, so an inferential method used by the study team is not reported in the registry record.
What does a single-group design estimate?
In a single-group study, the observed outcomes describe the participants who received the intervention. A proportion or event rate can summarize how common an outcome was in that group, provided the denominator, outcome definition, and observation period are clear. Such a summary does not establish what would have happened to the same participants under a different intervention. A control group can help estimate that contrast; this study has none.
Without a comparison group, factors other than the device may contribute to observed outcomes. These can include participant characteristics, the operation, and other elements of care. Statistical adjustment cannot automatically resolve this problem, especially when relevant variables and an analysis plan are not reported. The registry record does not describe an adjusted analysis.
Why distinguish participants from events?
A participant-based count records how many people experienced at least one event in a category. An event-based count records how many events occurred, potentially including repeated events in one person. These summaries answer different questions. The registry’s adverse-event fields report the number affected, while the primary endpoint is described as a number of device-related adverse events. The record does not provide enough detail to reconcile those descriptions or to identify recurrent events.
Seriousness and relationship to the device are also distinct classifications. An event may be classified as serious or other, and separately assessed for whether it is related to the device. The posted summary gives serious and other categories but does not provide a detailed event-level attribution breakdown. Consequently, the serious and other counts should not be treated as a direct device-causality analysis.
What would uncertainty measures add?
General explanation: a confidence interval gives a range of values compatible with the data under a specified statistical model and procedure. It conveys uncertainty around an estimate, rather than guaranteeing that the true value lies in the interval. With a small study group, estimates can be imprecise, and an event count of zero does not demonstrate that the underlying event risk is zero. The registry record does not report confidence intervals for the adverse-event figures.
A p-value evaluates how compatible data are with a specified null hypothesis under model assumptions. It does not measure the probability that a treatment works, nor does it replace an effect estimate and its uncertainty. No p-value or hypothesis test is listed for this study. In the absence of a comparator and a reported analysis, inferential claims about a treatment difference cannot be drawn from the posted counts.
How should planning illustrations be understood?
A sample-size calculation is a planning exercise based on assumptions about the outcome, effect to detect, significance level, power, and design. It is not an observed result and does not show whether a study had a particular probability of finding an effect after data collection. The registry’s planning illustration is based on an observed effect and assumes two arms with equal allocation, a two-sided significance level of 0.05, and a normal approximation. It describes participants per arm for non-time-to-event outcomes and total events for time-to-event outcomes.
Those assumptions do not match the registered single-group design. The illustration should not be read as the study’s actual design or as its sample-size justification. The registry record does not report the trial’s own sample-size justification, a prespecified effect size, or an inferential analysis plan. Sample-size planning values, where present, are hypothetical planning quantities and not observed power.
Why can adverse-event data be over-dispersed?
General explanation: event counts may vary more than a simple statistical model expects when some participants are more prone to events than others, when events cluster, or when follow-up differs. This is called over-dispersion relative to that model. It can make standard errors too small if ignored. The posted summary does not provide event-level counts or a model, so over-dispersion cannot be assessed from the registry record.
For this study, the clearest statistical reading is limited to the stated group counts, their denominator, and the endpoint timeframe. The enrollment and adverse-event denominators differ, the relationship of all events to the device is not detailed, and no analysis results or uncertainty measures are reported. Those are substantive limits on precision and interpretation, not details that can be repaired by assuming a particular statistical method.
10. Multiplicity, Missing Data and Analysis Populations
The registry lists three outcome measures: the primary safety outcome and two secondary outcomes concerning device operation and conversion to open surgery. It does not report a multiplicity strategy, such as a hierarchy of testing or an adjustment for assessing several outcomes. Because no analyses are listed, it is also not possible to determine whether formal hypothesis tests were conducted. The analysis plan is not reported in the registry record.
Multiplicity matters when several statistical tests are used: the chance of at least one apparently notable result can increase as more tests are considered. This is a general statistical concern, not evidence that a particular error occurred in this study. The record’s descriptive adverse-event counts do not themselves establish a multiple-testing problem.
Missing-data handling and analysis populations are also not described. Enrollment is 22, whereas the adverse-event summary lists 20 at risk. The reason for this difference, the number with complete 30-day follow-up, and any exclusions are not reported in the registry record. It is therefore not possible to determine whether the summary uses all enrolled participants, a safety population, or another defined group. No imputation method or sensitivity analysis is reported.
These omissions limit assessment of whether all outcomes were handled consistently and whether any incomplete follow-up could affect the posted summaries. They should not be filled in by assuming a conventional approach; the record does not state one.
11. Safety Results
The registry reports serious adverse events as affected participants divided by participants at risk.
| Arm | Participants with serious adverse events | Participants at risk | Percentage |
|---|---|---|---|
| DRAA (Dual Robotic Arm Accessory) | 0 | 20 | 0.0% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| DRAA (Dual Robotic Arm Accessory) | 0 of 20 |
Other (non-serious) adverse events
Participants with at least one non-serious event at or above the registry's 0% reporting threshold.
| Arm | Participants affected of at risk |
|---|---|
| DRAA (Dual Robotic Arm Accessory) | 12 of 20 |
Most frequent non-serious adverse event terms
| Event term | Organ system | DRAA (Dual Robotic Arm Accessory) |
|---|---|---|
| Petechia | Skin and subcutaneous tissue disorders | 4 of 20 |
| Ecchymosis in surgical wound | Skin and subcutaneous tissue disorders | 3 of 20 |
| Liver capsule minor abrasion without clinically relevant concern | Surgical and medical procedures | 3 of 20 |
| Allergic Rash | Skin and subcutaneous tissue disorders | 1 of 20 |
| Vomiting | Gastrointestinal disorders | 1 of 20 |
The safety summary lists 20 participants at risk in the DRAA group. It records 0 affected by serious adverse events and 12 affected by other adverse events. These figures describe participants in the posted categories; they do not state how many total events occurred or whether the same participant experienced multiple events. The record does not provide a detailed list of event terms.
The primary endpoint is described as device-related adverse events over 30 days, but the summary does not give a distinct event-by-event account of device relatedness. Seriousness and device relationship are not interchangeable classifications. The figures therefore should not be treated as proof that the 12 participants’ other adverse events were caused by the device, or that the 0 serious adverse events establishes absence of serious risk.
The adverse-event denominator of 20 differs from the enrollment of 22. Why two enrolled participants are not included in the at-risk count is not reported in the registry record. The record also does not report confidence intervals or further detail on follow-up. The counts are best understood as the posted descriptive safety summary for the DRAA group, with uncertainty and denominator context kept in view.
12. What the Result Does, and Does Not, Mean
The study provides a registry-record description of a single-group evaluation of the Dual Robotic Arm Accessory used with the Levita Magnetic Surgical System. Its adverse-event summary records 0 participants affected by serious adverse events and 12 affected by other adverse events among 20 listed at risk. The record also states a 30-day timeframe for the primary safety endpoint.
These observations do not establish that the device caused, prevented, or reduced adverse events. Without a control group, the results cannot estimate a comparative effect. The counts also do not establish the absence of serious risk: no serious events were recorded in the listed group, but the record does not provide an uncertainty interval or a detailed event account. The other-adverse-event count is not a count of device-related events unless attribution is documented, and that detail is not reported in the registry record.
The registry lists feasibility and conversion outcomes, but numerical results for them are not reported in the registry record. Thus the posted safety summary alone cannot answer how often the device successfully engaged, moved, and decoupled under surgeon control, or how often conversion to open surgery occurred.
Enrollment was 22, while 20 participants are listed at risk for the adverse-event summary. The reason is not reported. This difference complicates interpretation of the denominator and means that the safety counts cannot simply be assumed to cover all enrolled participants.
Overall, the record documents a completed, prospective, multicenter, open-label, single-arm study and reports descriptive adverse-event counts. It does not provide the detail needed for a controlled comparison, a complete assessment of the primary endpoint, or a statistical conclusion about comparative safety or feasibility.
13. Why This Trial Matters Statistically
Device studies often need to examine both whether a device can be used as intended and what adverse events occur during use. This record illustrates the statistical distinction between those questions: it lists a safety endpoint and feasibility-related outcomes, but provides a numerical adverse-event summary without numerical results for the listed secondary outcomes.
The single-group design is important for interpreting every count. It can describe what was recorded among participants exposed to the system, but it cannot isolate the effect of the device from other influences or estimate a contrast with another approach. This is a design limitation, not a flaw that a p-value or a larger set of descriptive statistics can remove.
The denominator difference is also statistically important. Enrollment is 22, while the adverse-event summary lists 20 at risk. Without an explanation of eligibility for the safety analysis or follow-up completeness, readers cannot establish how the denominator was formed. Clear definitions of the analysis population and outcome would make safety summaries easier to interpret.
The record’s limited reporting highlights why event definitions, attribution, follow-up, and uncertainty measures matter. Counts can be useful, but their meaning depends on whether they refer to participants or events, how seriousness and device relatedness were determined, and how completely participants were observed. Those details are not reported in the registry record.
Statistically, the study is most informative as a descriptive account rather than a comparative evaluation. Recognizing that distinction keeps the reported observations useful without extending them beyond what the design and record support.
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.
This is a single-group study, so it has no concurrent control group for estimating comparative safety or feasibility. Open-label conduct is stated, but the registry record does not describe procedures for outcome assessment or safeguards against assessment bias. The number and identities of participating centers are not reported.
The registry lists 22 enrolled participants, but the adverse-event summary lists 20 at risk. The reason for the denominator difference and the completeness of follow-up are not reported in the registry record. The available safety summary does not provide event terms, recurrent-event counts, or a detailed breakdown of device relatedness. It also does not report confidence intervals or other measures of uncertainty.
The record lists a primary safety endpoint and two secondary outcomes, but numerical results for the secondary outcomes are not reported in the registry record. A detailed definition of the primary outcome, including how device relatedness was assessed, is also not reported. No analyses are listed, and the statistical analysis plan, missing-data approach, analysis populations, and multiplicity strategy are not reported.
The registry’s sample-size illustration assumes a two-arm design, while this study is registered as single-group. It should not be treated as the study’s actual design or as a reported justification for enrollment. These limitations mean that the available information supports only a cautious description of the posted safety counts, rather than a complete or comparative statistical assessment.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: Safety and Feasibility of the Use of the Dual Robotic Arm Accessory With the Levita Magnetic Surgical System in Laparoscopic Procedures — NCT05695989.
- Registry record last updated 2025-02-21; status last verified 2025-01.
- Results first posted 2025-02-21.
- 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.
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18. Record Summary
The registry identifies NCT05695989 as a completed, prospective, multicenter, single-arm, open-label study of the Dual Robotic Arm Accessory with the Levita Magnetic Surgical System in laparoscopic procedures. Enrollment is listed as 22; the study began on 2023-01-19 and its primary completion date is 2023-03-08.
The primary endpoint concerns device-related adverse events over 30 days. The posted adverse-event summary lists 20 participants at risk, with 0 affected by serious adverse events and 12 affected by other adverse events. The registry also lists outcomes for device engagement, movement, and decoupling, and conversion to open surgery, but numerical results for those outcomes are not reported in the registry record.
No analyses are listed. The reason for the difference between enrollment and the adverse-event denominator, detailed event attribution, and a statistical analysis plan are not reported in the registry record. The available results are descriptive and do not provide a controlled comparison.