Investigation of adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents in the iliac vein: insights into developing a better iliac vein stent

Assessing the Reproducibility of Research Based on the Food and Drug Administration Manufacturer and User Facility Device Experience Data

OBJECTIVE

This article aims to assess the reproducibility of Manufacturer and User Facility Device Experience (MAUDE) data-driven studies by analyzing the data queries used in their research processes.

METHODS

Studies using MAUDE data were sourced from PubMed by searching for "MAUDE" or "Manufacturer and User Facility Device Experience" in titles or abstracts. We manually chose articles with executable queries. The reproducibility of each query was assessed by replicating it in the MAUDE Application Programming Interface. The reproducibility of a query is determined by a reproducibility coefficient that ranges from 0.95 to 1.05. This coefficient is calculated by comparing the number of medical device reports (MDRs) returned by the reproduced queries to the number of reported MDRs in the original studies. We also computed the reproducibility ratio, which is the fraction of reproducible queries in subgroups divided by the query complexity, the device category, and the presence of a data processing flow.

RESULTS

As of August 8, 2022, we identified 523 articles from which 336 contained queries, and 60 of these were executable. Among these, 14 queries were reproducible. Queries using a single field like product code, product class, or brand name showed higher reproducibility (50%, 33.3%, 31.3%) compared with other fields (8.3%, P = 0.037). Single-category device queries exhibited a higher reproducibility ratio than multicategory ones, but without statistical significance (27.1% versus 8.3%, P = 0.321). Studies including a data processing flow had a higher reproducibility ratio than those without, although this difference was not statistically significant (42.9% versus 17.4%, P = 0.107).

CONCLUSIONS

Our findings indicate that the reproducibility of queries in MAUDE data-driven studies is limited. Enhancing this requires the development of more effective MAUDE data query strategies and improved application programming interfaces.

Stent deformations in the common iliac and iliofemoral veins as a result of hip flexion and extension

OBJECTIVE

In the present study, we characterized deformations of venous stents implanted into common iliac veins for nonthrombotic iliac vein lesions and iliofemoral veins for deep vein thrombosis due to hip movements commensurate with everyday activities such as walking, sitting, and stair climbing.

METHODS

Patients treated with iliofemoral venous stents were recruited from three centers and underwent imaging with two orthogonal two-dimensional projection radiographs. Stents in the common iliac veins and iliofemoral veins crossing the hip joint were imaged with the hip in 0°, 30°, 90° and -15°, 0°, and 30° positions, respectively. Using the radiographs, the three-dimensional geometries of the stents were constructed for each hip position, and the diametric and bending deformations between those positions were quantified.

RESULTS

Twelve patients were included, and the findings showed that the common iliac vein stents experienced approximately twofold more local diametric compression with 90° hip flexion compared with 30° flexion. Also, iliofemoral vein stents crossing the hip joint experienced significant bending with hip hyperextension (-15°) but not with hip flexion. In both anatomic locations, maximum local diametric and bending deformations were in proximity with each other.

CONCLUSIONS

Stents implanted in the common iliac and iliofemoral veins exhibit greater deformation during high hip flexion and hyperextension, respectively, and iliofemoral venous stents interact with the superior ramus of the pubis during hyperextension. These findings suggest that device fatigue could be influenced by the type and level of patient physical activity, in addition to anatomic positioning, opening up the potential benefit of activity modification and the use of a careful implantation strategy. The proximity of maximum diametric and bending deformations means that simultaneous multimodal deformations should be considered for device design and evaluation.

Endovascular Repair of Iatrogenic Inferior Vena Cava and Iliac Vein Injury: A Case Series and Review of the Literature

OBJECTIVE

Iatrogenic injury to the large abdominopelvic veins can he highly morbid, and open surgical repair is technically challenging. Endovascular repair with covered stenting across the injured segment offers an alternative to open surgical management. We present a series of patients with operative injury to the inferior vena cava (IVC) and iliac veins who were treated utilizing an endovascular approach and review the available literature on this technique.

METHODS

A PubMed keyword and MeSH term search was performed, and titles were reviewed for relevance by the first author. Studies related to endovascular repair of iatrogenic injury to the IVC and iliac veins were then read in detail for possible inclusion in the review. Those deemed appropriate were further analyzed for interventional approach, stent type and size, technical success, post-procedural pharmacologic management, complications and surveillance strategy.

RESULTS

The initial search resulted in 6221 publications. A total of 17 met criteria for inclusion, all of which were case reports or series. Twenty-six patients were described as suffering iatrogenic injury to the IVC or iliac veins, treated with various types and sizes of stents. All cases achieved technical success with hemorrhage control. Procedural complications occurred in 15.4% of cases, including 3 cases of acute thrombus formation and 1 case of stenosis caudal to the initial stent edge requiring additional stenting. Two additional patients experienced stent occlusion in the surveillance period.

CONCLUSIONS

Endovascular repair of iatrogenic injury to the IVC and iliac veins can be an effective management option. However, due to limited data regarding this approach, many technical questions remain, including ideal size and type of stent graft, necessity and duration of post-procedural anticoagulant or antiplatelet therapy and appropriate surveillance. Additionally, long term outcomes in this population have not yet been described.

Performance of Open and Closed Cell Laser Cut Nitinol Stents for the Treatment of Chronic Iliofemoral Venous Outflow Obstruction in Patients Treated at a Single Centre

OBJECTIVE

A number of dedicated self expanding nitinol stents have been developed for use in the venous system, with both open cell (OC) and closed cell (CC) designs available. Data comparing these different designs are lacking. The objective of this study was to evaluate outcomes in patients treated with open and closed cells for unilateral chronic iliac vein obstruction.

METHODS

A single centre retrospective cohort study was conducted, including all patients treated with a dedicated nitinol venous stent between 2014 and 2019. Stent patency and details of re-interventions (including lysis, venoplasty, reinforcement, extension, arteriovenous fistula formation) were examined in the first post-operative year. Subgroup analysis described outcomes for patients treated with OC and CC stents ending above the inguinal ligament and those who required extension into the common femoral vein. Cox regression analysis was used to identify factors associated with loss of primary patency.

RESULTS

A total of 207 patients were included (OC 100 patients, CC 107 patients). There was no significant difference between the groups for age (OC 42 years, CC 44 years); gender (OC and CC 67% female); presence of post-thrombotic lesions (OC 71%, CC 73%); stenting across the inguinal ligament (OC 58%, CC 56%), or presence of inflow disease (OC 49%, CC 47%). Primary and cumulative patency at 12 months were similar between groups (primary: OC 63%, CC 65%; cumulative: OC 93%, CC 90%). Patients with a CC stent across the inguinal ligament had a greater risk of needing multiple re-interventions at one year compared with those with an OC stent (odds ratio 2.84, 95% confidence interval [CI] 1.16 - 6.9) but overall, the only factor significantly associated with loss of primary patency was inflow vessel disease (hazard ratio 3.39, 95% CI 1.73 - 6.62, p < .001).

CONCLUSION

OC and CC dedicated nitinol venous stents were observed to perform similarly in terms of patency and symptom improvement at one year. Disease of the inflow vessels was the most important factor associated with a loss of stent patency irrespective of stent design.

A Systematic Review and Meta-Analysis of 12-Month Patency After Intervention for Iliofemoral Obstruction Using Dedicated or Non-Dedicated Venous Stents

BACKGROUND

Endovascular stenting of the deep venous system has been proposed as a method to treat patients with symptomatic iliofemoral outflow obstruction. The purpose of this systematic review and meta-analysis was to compare the effectiveness of this treatment at 1-year following the development of dedicated venous stents.

METHOD AND RESULTS

We searched MEDLINE and EMBASE for studies evaluating the effectiveness of venous stent placement. Data were extracted by disease pathogenesis: non-thrombotic iliac vein lesions (NIVL), acute thrombotic (DVT), or post-thrombotic syndrome (PTS). Main outcomes included technical success, stent patency at 1 year and symptom relief. A total of 49 studies reporting outcomes in 5154 patients (NIVL, 1431; DVT, 950; PTS, 2773) were included in the meta-analysis. Technical success rates were comparable among groups (97%-100%). There were no periprocedural deaths. Minor bleeding was reported in up to 5% of patients and major bleeding in 0.5% upon intervention. Transient back pain was noted in 55% of PTS patients following intervention. There was significant heterogeneity between studies reporting outcomes in PTS patients. Primary and cumulative patency at 1 year was: NIVL-96% and 100%; DVT-91% and 97%; PTS (stents above the ligament)-77% and 94%, and; PTS (stents across the ligament)-78% and 94%. There were insufficient data to compare patency outcomes of dedicated and nondedicated venous stents in patients with acute DVT. In NIVL and PTS patients, stent patency was comparable at 1 year. There was inconsistency in the use of validated tools for the measurement of symptoms before and after intervention. When reported, venous claudication, improved in 83% of PTS patients and 90% of NIVL patients, and ulcer healing occurred in 80% of PTS patients and 32% of NIVL patients.

CONCLUSIONS

The first generation of dedicated venous stents perform comparably in terms of patency and clinical outcomes to non-dedicated technologies at 1 year for the treatment of patients with NIVL and PTS. However, significant heterogeneity exists between studies and standardized criteria are urgently needed to report outcomes in patients undergoing deep venous stenting.

A systematic review of the quality of cardiovascular surgery studies that extracted data from the MAUDE database

OBJECTIVE

To investigate opportunities and limitations of using the Manufacturer and User Facility Device Experience (MAUDE) database for cardiovascular surgery research, we analyzed the quality of studies having ever used MAUDE, in the field of cardiovascular surgery.

METHODS

We systematically searched the Cochrane Library, PubMed, EMBASE, and Google Scholar for randomized and nonrandomized studies, from inception to July 2019. Two authors evaluated the quality of the retrieved observational studies, according to the National Institutes of Health quality assessment tool for either case series or cross-sectional studies. These tools quantify the quality of case series and cohorts/cross-sectional studies, respectively, with nine and 14 queries.

RESULTS

Fifty-eight studies were included in the final qualitative review. Of 58 identified studies, 32 were case series, 8 were abstracts of case series, and 13 were reviews or case discussion with an included series from MAUDE. Also, five articles were cross-sectional studies. Of the 32 formal case series, 26 (81%) were found to have poor quality. The most common reasons for a poor quality designation included a lack of consecutive participants, undetermined comparability of participants, and undetermined follow-up adequacy. Only one out of five cross-sectional studies had fair quality; four others were evaluated as poor quality studies.

CONCLUSIONS

Cardiovascular surgery studies using the MAUDE database, whether case series or cross-sectional design, are mostly of poor quality. Their low quality is partly caused by poor study design, but mainly by intrinsic limitations to the MAUDE database: cases recruited are not consecutive; patient characteristics are not detailed enough to allow a meaningful comparison of patient characteristics between different patient entries; outcome measures are unclear; there is a limited follow-up; and time-to-event data are lacking. We conclude that the quality of cardiovascular surgery publications that rely on data from MAUDE could be improved if investigators were to extract all relevant data points from MAUDE entries, then apply standard quality assessment tools in compiling and reporting the data. MAUDE might be improved if it used medical case report standards during the process of reporting and indexing adverse events. To calculate the incidence rate of any adverse event, all event-free cases, as well as all adverse events in patients using a device, are required. Neither of these two variables is available in the MAUDE at the time of writing.

An image analysis of the major angles along the pathway of iliac veins involved in endovenous interventions

OBJECTIVE

The specific anatomic characteristics of the iliac veins are often important reasons for stent failure. However, to the best of our knowledge, the inherent angles and configurations of the iliac veins have not been thoroughly studied.

METHODS

Fifty patients without venous diseases who had undergone computed tomography urography for diagnosis of urolithiasis were included in this study. The pathways of the iliac veins were mapped out, and the major angles were measured. The factors associated with steep angles were also evaluated.

RESULTS

There were two relatively constant angles on the right side and three on the left side along the common femoral vein, external iliac vein, and common iliac vein. All these were measured with the patients in the supine position. The angles at the inguinal region (γ) and internal-external iliac vein confluence (β) were at similar sites for both sides. There was a third angle in front of the fifth vertebra for the left side (α). The γ angle was 125.03 ± 11.68 degrees for the right side and 122.26 ± 9.64 degrees for the left side. The β angle was 136.91 ± 14.24 degrees for the right side and 125.61 ± 20.76 degrees for the left side. According to the β angle of the left side, the iliac veins could be categorized into three types. For type I, the angle was >150 degrees (14% [7/50]). For type II, it was 120 to 150 degrees (50% [25/50]). For type III, it was ≤120 degrees (36% [18/50]). The angles between the anterior border of the fifth vertebra and pelvic inlet plane (0.866; 95% confidence interval, 0.777-0.966) and age (1.087; 95% confidence interval, 1.004-1.177) were related to type III configurations on multilogistic regression analysis.

CONCLUSIONS

There were several relatively constant angles along the pathway of the iliac veins. The pathway of the left side was more complex than that of the right side. This difference in the angles might be related to the patients' age and bone structures. These angles should be considered in planning iliac vein stenting as well as in designing stents specifically for the iliac veins.

Covered Stent Implantation for Treatment of Iliac Vein Rupture During Percutaneous Left Atrial Appendage Occlusion

An 82-year-old woman who experienced an iatrogenic external iliac vein perforation during a left atrial appendage occlusion procedure was successfully treated by endovascular graft implantation. We report the short- and long-term outcomes of the procedure. (Level of Difficulty: Advanced.).