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 DETOUR I Clinical Study for Percutaneous Femoropopliteal Bypass (NCT02471638), a na na study. The primary outcome is Number of Lesions With Primary Patency.
| Feature | Registry value |
|---|---|
| ClinicalTrials.gov identifier | NCT02471638 |
| Phase | NA |
| Condition | Peripheral Arterial Disease |
| Allocation | Not applicable (single group) |
| Design model | Single Group |
| Masking | None (open label) |
| Enrollment | 78 |
| Arms in the primary outcome | n/a |
| Lead sponsor | Endologix |
| Results posted | Yes |
2. Clinical Question
Population
People with peripheral arterial disease enrolled in the DETOUR I clinical study. The registry record describes 78 enrolled and treated patients, but does not report the primary endpoint population characteristics or the number of lesions assessed.
Intervention
The PQ Bypass System for Femoropopliteal Bypass, a device intended to access and deliver guidewires and implant stent grafts to complete a percutaneous femoropopliteal bypass.
Comparator
There was no separate comparator group. The study is recorded as a single-group study, with allocation and masking recorded as not applicable and none, respectively.
Primary question
How many lesions had primary patency at 6 months? Patency was defined by the absence of clinically significant stenosis in or immediately adjacent to the stent graft, assessed using duplex ultrasound criteria.
This question is about the observed performance of the device in the study group, not whether it performed better than another procedure or device. Without a concurrent comparator, the registry record cannot show how outcomes would have differed under another treatment approach. It also does not report the primary endpoint count, so the primary patency result itself cannot be interpreted from the registry record.
3. Trial Design
DETOUR I, also titled PQ Bypass Systems for Femoropopliteal Bypass II (PQB 4 FP II), is recorded as a completed, single-group clinical study sponsored by Endologix. The registry describes 78 enrolled participants with peripheral arterial disease. The study start is recorded as 2015-01 and primary completion as 2018-09.
The intervention was the PQ Bypass System for Femoropopliteal Bypass. The registry summary describes the study purpose as assessing the safety and performance of the system for accessing and delivering guidewires and implanting stent grafts for a percutaneous femoropopliteal bypass. The study arm description likewise refers to use of the system to complete that procedure.
No separate control arm is recorded. Allocation is listed as not applicable, and masking as none. Consequently, the design is not a randomized comparison, and outcomes in the study group cannot be contrasted with outcomes under a concurrent control condition. The registry record does not report a protocol-based comparator or a statistical plan for a between-group analysis.
The primary outcome is the number of lesions with primary patency at 6 months. The registry also lists secondary outcomes addressing patency, adverse events, vascular events, deep vein thrombosis, and technical success at specified time points. The listed outcome measures do not by themselves establish that results were reported for each measure. The record lists no analyses, and the primary endpoint result is not reported in the registry record.
4. Participant Flow and Accounting
The registry reports how participants moved through each stage of the study. All counts below are exactly as posted; missing counts are not inferred from other stages.
Overall Study
| Stage | Enrolled and Treated Patients |
|---|---|
| STARTED | 78 |
| 12 Month Results | 77 |
| COMPLETED | 68 |
| NOT COMPLETED | 10 |
Reasons for not completing this period:
| Reason | Enrolled and Treated Patients |
|---|---|
| Early Term Withdrawal | 10 |
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: Overall Number of Baseline Participants enrolled 78, and Overall Number of Lesions (units) analyzed 82.
| Characteristic | Unit | Enrolled and Treated Patients |
|---|---|---|
| Participants analysed | 78 | |
| Age, Continuous | years | 65 (SD 7) |
| Sex: Female, Male: Female | Participants | 13 |
| Sex: Female, Male: Male | Participants | 65 |
| Region of Enrollment: New Zealand | Lesions | 1 |
| Region of Enrollment: Latvia | Lesions | 34 |
| Region of Enrollment: Poland | Lesions | 36 |
| Region of Enrollment: Italy | Lesions | 1 |
| Region of Enrollment: Chile | Lesions | 7 |
| Region of Enrollment: Germany | Lesions | 3 |
| Hypertension | Participants | 65 |
| Diabetes mellitus | Participants | 20 |
| Hypercholesterolemia | Participants | 31 |
| History of Coronary Artery Disease (CAD) | Participants | 34 |
| History of smoking | Participants | 68 |
| Previous peripheral vascular intervention | Participants | 19 |
| SFA lesion length | mm | 371 (SD 55) |
| Ankle Brachial Index (ABI) | Ratio | 0.64 (SD 0.17) |
| TASC Lesion Type: TASC Lesion Type C | Lesions | 46 |
| TASC Lesion Type: TASC Lesion Type D | Lesions | 36 |
| Chronic Total Occlusion | Lesions | 79 |
6. Primary Endpoint
The registry lists the primary outcome as Number of Lesions With Primary Patency, measured over 6 Months.
| Element | Registry entry |
|---|---|
| Result type | Count Of Units |
| Measure of spread | not applicable |
| Unit | Lesions |
| Endpoint classification | not reduced to a single comparison |
The primary endpoint is the number of lesions with primary patency at 6 months. The registry defines primary patency as no evidence of clinically significant stenosis, specified as ≥50%, within the stent graft or immediately above or below the treated arterial segment. The assessment is based on duplex ultrasound, with a systolic velocity ratio criterion of >2.5.
Patency is a measure of whether the treated arterial pathway remains open without the specified evidence of narrowing. It is used to describe device and procedure performance over follow-up. The endpoint is expressed as a count of lesions, rather than a reported percentage in the primary outcome description. Lesions and participants are not interchangeable units: a participant may have a different number of treated lesions, and the registry record does not state how many lesions were assessed.
The record gives the endpoint timeframe and definition, but not the observed count, a denominator for calculating a proportion, or an uncertainty interval. The primary patency result is therefore not reported in the registry record. The definition explains what would qualify as patent; it does not establish how many lesions met that definition.
7. Why No Re-analysis Is Shown
8. Statistical Interpretation
The registry record identifies a clinically relevant device-performance question: whether treated lesions met a duplex-ultrasound definition of primary patency at 6 months. However, it does not report the observed primary endpoint count. As a result, the posted registry information does not establish the level of patency observed in this study, and it does not support a numerical estimate of the primary endpoint or its precision.
The study is single-group, with no concurrent comparator. This matters for interpretation even if a group outcome is available: an observed outcome in one group cannot, on its own, distinguish the effect of the device from other influences on outcomes. The design can describe what occurred among participants treated in the study, but it cannot directly estimate a difference relative to another treatment or usual care.
The registry lists adverse-event information for enrolled and treated patients. It reports 14 affected by serious adverse events among 78 at risk, 65 affected by other adverse events among 78 at risk, and 3 deaths. Those counts describe events recorded in the registry; the available information does not establish their causes, timing, severity beyond the registry classifications, or relationship to the device or procedure. Serious-event terms and percentages are also listed, but their counting and denominator conventions are not reported in the registry record.
Several additional outcomes are listed, including patency at 12 months, major adverse vascular events, symptomatic deep vein thrombosis, adverse events at later time points, and technical success. The presence of an outcome in a registry listing is not evidence that its result is available. Results for these measures are not reported in the registry record in the information summarized for this study.
Precision cannot be assessed for the primary endpoint because no endpoint estimate or confidence interval is reported. General statistical interpretation would use an uncertainty interval to show the range of values reasonably compatible with the observed data under the analysis assumptions. Without the endpoint count, the number of lesions assessed, or an interval, readers cannot assess either the result’s magnitude or its statistical precision. No conclusion that the device succeeds or fails follows from a missing result.
9. Statistical Methods Explained
The methods information in the registry record is limited. It identifies a single-group study, a lesion-count primary outcome, an endpoint definition, and a 6-month timeframe. It does not report a detailed statistical analysis plan, the primary endpoint result, or an analysis population for that endpoint. The following explanations distinguish general statistical principles from methods documented for this study.
What does a lesion count describe?
The primary outcome is a count of lesions meeting the patency definition, not a directly reported rate. To interpret a count as a proportion, a reader would need to know the number of lesions assessed and how missing or unassessable lesions were handled. The registry record does not report those details. The number of enrolled and treated patients is not a substitute for the number of lesions, because the outcome’s unit is lesions and the record does not specify the lesion count.
In general, a count may be analyzed as a count, or used to estimate a proportion when an appropriate denominator is available. The choice depends on the outcome’s structure and the study question. A proportion would usually be accompanied by an uncertainty interval, which conveys how much estimation uncertainty remains. No such primary endpoint estimate or interval is reported in the registry record.
What does the patency definition contribute?
The definition makes the endpoint operational: it specifies the anatomical locations to assess, the stenosis threshold, and the ultrasound-based criterion. A clear operational definition helps readers understand what qualifies as an event or outcome and can support consistent measurement. It does not, by itself, show whether assessment was blinded, how measurements were adjudicated, how often ultrasound assessments were missing, or how borderline readings were resolved. Those procedural details are not reported in the registry record.
In general, a threshold-based endpoint can be sensitive to measurement variability near the cutoff. Consistent imaging methods and prespecified assessment procedures help reduce differences caused by measurement rather than underlying clinical status. The record states the duplex-ultrasound definition but does not describe such implementation details. The criterion’s exact wording is part of the endpoint definition, not a reported outcome result.
How should a single-group study be read?
A single-group analysis can describe outcomes among participants who received the intervention. It does not provide a randomized contrast that separates treatment effects from other explanations for the observed outcome. General statistical adjustment cannot fully replace a concurrent randomized control when unmeasured differences or changes over time could influence outcomes. The registry record does not report a comparator group or a comparative analysis.
Accordingly, a within-group count or rate, if reported, would answer a descriptive question about observed outcomes in the study group. It would not by itself estimate how outcomes would have differed under another intervention. This is a design limitation, not a calculation problem that can be solved by converting a count into a percentage.
What does the sample-size planning language mean?
The record describes sample-size illustrations as planning calculations based on an observed effect, with a two-sided significance level of 0.05, equal allocation between two arms, and a normal approximation. It states that the effect to detect is a specified fraction of the observed effect. For time-to-event tables, it describes total event counts using the Schoenfeld approach; other tables are described in participants per arm.
These are planning assumptions, not evidence that the single-group study was designed or conducted as a two-arm trial. The assumptions do not establish the study’s original sample-size rationale, which is not reported in the registry record. Planning calculations are not observed power: they describe hypothetical future designs under stated assumptions. The record does not report the trial’s own sample-size justification or an interim-analysis plan.
In general, planning estimates depend on assumptions about the outcome, the effect worth detecting, variability, allocation, and the analysis. If those assumptions differ from a later study’s actual conditions, the planned sample size may not yield the intended precision or operating characteristics. A planning illustration should therefore be read as conditional rather than as a guarantee.
Why can over-dispersion matter?
In general, over-dispersion occurs when count outcomes vary more than a simple statistical model expects. A model that assumes less variability than the data contain can produce uncertainty intervals that are too narrow and tests that are too optimistic. Appropriate modeling may account for extra variability, clustering, or repeated observations, depending on the data structure.
The registry record does not report a model for the primary count, an estimate of its variability, or whether lesions were clustered within participants in the analysis. It is therefore not possible to assess whether an over-dispersion adjustment was needed or used. This is a general consideration for count outcomes, not a claim that over-dispersion occurred in this study.
10. Multiplicity, Missing Data and Analysis Populations
The registry record lists 10 outcome measures, including the primary patency endpoint and secondary measures covering patency, adverse events, vascular events, deep vein thrombosis, and technical success. When multiple outcomes or time points are examined, the chance of at least one apparently unusual result can increase if each is tested separately. General approaches to this issue include prespecifying a primary outcome, adjusting inference across a family of tests, or treating secondary findings as descriptive. The registry record does not report a multiplicity strategy or a detailed statistical analysis plan.
The record lists no analyses. It does not report how missing endpoint assessments were handled, whether analyses used all enrolled participants or a defined subset, or how participants or lesions without evaluable follow-up were treated. The primary endpoint population is not specified in the registry record. These omissions matter because exclusions and missing assessments can change the group represented by an estimate and can affect its interpretation.
In general, missing-data methods rely on assumptions about why data are missing. Complete-case analysis, imputation, and sensitivity analyses answer different questions and can lead to different results when missingness is substantial or related to outcomes. No particular approach can be attributed to this study from the registry information. Readers cannot assess whether missingness could have biased the primary outcome without information on the amount, reasons, and analysis of missing data.
The absence of a reported analysis plan also prevents assessment of whether outcome definitions, time points, and analytic choices were specified before results were examined. These features are not reported in the registry record; their absence from the record should not be treated as proof that no such procedures existed outside it.
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 |
|---|---|---|---|
| Enrolled and Treated Patients | 14 | 78 | 17.9% |
Deaths
| Arm | Deaths (participants affected of at risk) |
|---|---|
| Enrolled and Treated Patients | 3 of 78 |
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 |
|---|---|
| Enrolled and Treated Patients | 65 of 78 |
Most frequent serious adverse event terms
| Event term | Organ system | Enrolled and Treated Patients |
|---|---|---|
| Stent Thrombosis | Vascular disorders | 13 of 78 |
| Clinically Driven Target Vessel Revascularization (CD-TVR) | Surgical and medical procedures | 12 of 78 |
| Deep Vein Thrombosis (DVT) | Vascular disorders | 2 of 78 |
| Bleeding event requiring transfusion | Surgical and medical procedures | 1 of 78 |
| Target Limb Amputation | Surgical and medical procedures | 0 of 78 |
| Clinically apparent distal embolization | Vascular disorders | 0 of 78 |
| Procedure-related arterial rupture | Vascular disorders | 0 of 78 |
| Acute limb ischemia | Vascular disorders | 0 of 78 |
Most frequent non-serious adverse event terms
| Event term | Organ system | Enrolled and Treated Patients |
|---|---|---|
| Stent Graft thrombosis | Vascular disorders | 13 of 78 |
| Stent Graft Stenosis | Vascular disorders | 10 of 78 |
| Edema | Blood and lymphatic system disorders | 7 of 78 |
| Deep Vein Thrombosis | Vascular disorders | 4 of 78 |
| Reflux | Vascular disorders | 4 of 78 |
| Pain | General disorders | 4 of 78 |
| Access site hemorrhage or hematoma | Vascular disorders | 3 of 78 |
| Drug Reaction | Injury, poisoning and procedural complications | 3 of 78 |
| Fever | General disorders | 3 of 78 |
| Target Vessel Revascularization (TVR) | Vascular disorders | 3 of 78 |
Serious events with the highest arm-level rate: stent thrombosis (16.7%), clinically driven target vessel revascularization (cd-tvr) (15.4%), deep vein thrombosis (dvt) (2.6%), bleeding event requiring transfusion (1.3%), target limb amputation (0.0%).
The registry lists the safety group as enrolled and treated patients, with 78 at risk for both serious and other adverse events. It reports 14 affected by serious adverse events, 65 affected by other adverse events, and 3 deaths. These are registry-listed counts, not a comparative estimate of excess risk. The record does not report the timing or causes of deaths, or establish whether any event was attributed to the device or procedure.
The registry also lists serious adverse-event terms with percentages: Stent Thrombosis, 16.7%; Clinically Driven Target Vessel Revascularization (CD-TVR), 15.4%; Deep Vein Thrombosis (DVT), 2.6%; Bleeding event requiring transfusion, 1.3%; Target Limb Amputation, 0.0%; and Clinically apparent distal embolization, 0.0%. The denominator and counting convention for these term-specific percentages are not reported in the registry record. They should not be interpreted as rates per participant or as mutually exclusive categories without that information.
In general, adverse-event counts and percentages describe recorded safety observations; they do not establish causation. A single-group study also cannot provide a controlled estimate of how event occurrence compares with another treatment. The figures should therefore be read as descriptive registry reports, with attribution and comparative risk not reported.
12. What the Result Does, and Does Not, Mean
The record identifies what DETOUR I was designed to examine: use of the PQ Bypass System for femoropopliteal bypass, including a primary patency outcome assessed at 6 months. It also provides a definition for patency and lists safety outcomes. This information helps clarify the study question and the intended measurement, but it does not supply the primary patency result.
Because the study is recorded as single-group, any outcome would describe participants treated in the study rather than a randomized difference from a control group. A descriptive finding could be useful for understanding what was observed in this study, but it would not isolate the device’s effect from other influences. No comparative conclusion can be drawn from the design recorded.
The safety information includes counts for serious and other adverse events and deaths, as well as selected serious-event terms and percentages. Those reports do not, without further information, establish causal attribution, timing, or relative risk. The registry record does not report the denominator convention for the listed term-specific percentages or enough detail to assess missing safety observations.
What the record does not establish is equally important. It does not report the primary patency count, the number of lesions assessed, an uncertainty interval, a detailed analysis plan, or the handling of missing endpoint data. The secondary outcome listings do not substitute for outcome results. Readers therefore cannot use this registry information to quantify primary endpoint performance or precision.
These limits are about the information available in the registry record and the study’s recorded design. They are not evidence that the device did or did not achieve a particular clinical outcome. A treatment conclusion would require results and an appropriate basis for comparison, neither of which is established by the reported primary endpoint information.
13. Why This Trial Matters Statistically
This study is statistically notable because its primary endpoint is a lesion-level count while the record describes enrollment at the patient level. Keeping those units distinct is essential: patient enrollment does not reveal how many lesions were assessed. Without the lesion denominator and endpoint count, neither a primary patency proportion nor its precision can be evaluated.
The record also illustrates the difference between a carefully defined outcome and a reported result. The patency definition specifies the clinical and ultrasound criteria, which makes the intended measurement understandable. But a definition cannot replace the observed data, and a specified follow-up time cannot show how many lesions met the criteria.
Design determines what an analysis can answer. A single-group study can describe observations among treated participants, but it cannot provide a randomized comparison against another approach. Even a precise estimate from one group would not, on its own, identify the causal effect of the intervention. Here, the primary estimate itself is not reported, further limiting interpretation.
The safety listings also show why denominator and attribution details matter. Event counts and percentages are more informative when readers know how events were counted, the population at risk, the observation period, and whether investigators considered events related to treatment. Those details are not reported for the listed serious-event terms.
Finally, the record’s planning assumptions should not be confused with the trial’s design or with observed statistical power. Planning calculations depend on assumptions and address hypothetical future studies. They cannot supply missing outcome results or overcome the absence of a comparator. Together, these points make the record useful for understanding the study question and its limits, while leaving the main endpoint’s magnitude and precision unresolved.
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 primary limitation for interpreting the study results from this record is that the primary patency outcome result is not reported in the registry record. The record also does not report the number of lesions evaluated, the endpoint denominator, or an uncertainty interval. Since the endpoint is defined as a count of lesions, the patient enrollment figure does not resolve those omissions.
The study is single-group and has no recorded comparator. That design limits causal interpretation and does not support a direct estimate of how outcomes compare with another procedure or treatment. Masking is recorded as none, but the registry record does not explain whether endpoint assessors or imaging reviewers used any other procedures to reduce assessment bias.
The primary endpoint population, analysis methods, and handling of missing data are not reported in the registry record. The record also does not specify how lesion-level observations were handled if more than one lesion was associated with a participant. Without these details, the analytic unit, dependence structure, and influence of incomplete follow-up cannot be assessed.
Safety information is presented as counts and selected term-specific percentages, but the denominator and counting conventions for the term percentages are not reported. Timing, causes of death, and event attribution are also not reported. The registry lists secondary outcomes, but their results are not reported in the information available for this analysis. These are limitations of interpretation from the registry record, not evidence that additional information was never collected.
15. Related Tutorials
16. Related Statistical Calculators
17. Sources
- ClinicalTrials.gov: DETOUR I Clinical Study for Percutaneous Femoropopliteal Bypass — NCT02471638.
- Registry record last updated 2026-06-15; status last verified 2026-06.
- Results first posted 2025-05-23.
- 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
DETOUR I Clinical Study for Percutaneous Femoropopliteal Bypass (NCT02471638), also titled PQ Bypass Systems for Femoropopliteal Bypass II (PQB 4 FP II), is recorded as a completed single-group device study sponsored by Endologix. The registry lists 78 enrolled participants with peripheral arterial disease and describes use of the PQ Bypass System for Femoropopliteal Bypass.
The primary outcome is the number of lesions with primary patency at 6 months, defined using duplex-ultrasound criteria. The primary endpoint result, lesion denominator, analysis plan, and handling of missing endpoint data are not reported in the registry record. No comparator group is recorded.
The safety record lists 14 affected by serious adverse events, 65 affected by other adverse events, and 3 deaths among the 78 at risk. The record also lists selected serious-event terms and percentages, without reporting their denominator convention or causal attribution.