Introducer curving technique for the prevention of tilting of transfemoral Günther Tulip inferior vena cava filter

The Inferior Vena Cava Filter Placement Parameters May Predict Filter Retrieval Outcomes

BACKGROUND

We aimed to investigate the potential correlation between the placement factors of various retrievable inferior vena cava filters and retrieval outcomes. Additionally, we aimed to identify the factors affecting the placement tilt of the filter.

METHODS

This retrospective study was conducted at a tertiary care center to investigate patients who had previously undergone retrievable filter placement at our center and who subsequently had their filters removed between January 2020 and December 2021. Patient characteristics and filter-related factors were recorded. Complex filter retrieval was defined as cases that required a minimum of 8 minutes of fluoroscopy or that involved advanced techniques. Regression models were used to explore patient- and placement procedure-related factors that could influence retrieval outcomes and the placement tilt angle.

RESULTS

The study included 163 patients, and all filters were successfully retrieved. Thirty-seven (22.7%) retrievals were classified as complex retrievals. The mean diameter of the inferior vena cava in the preplacement position for the entire cohort was 16 ± 1.8 mm. The median filter tilt angles at placement and retrieval were 5.0° (IQR, 1.8°-9°) and 4.6° (IQR, 2.1°-8.0°), respectively. The placement tilt angle was not significantly associated with complex retrieval (P = 0.59). The filter hook abutment to the vena cava wall (OR, 10.76, P = 0.003), dwell time (OR, 1.02, P = 0.029), and diameter of the vena cava (OR, 10.21, P < 0.001) were associated with complex retrieval. The diameter (P = 0.049), age (P = 0.049), and filter brand (P = 0.001) were found to be significantly associated with placement tilt.

CONCLUSIONS

The inferior vena cava diameter at the time of placement predicts difficulty in filter retrieval. In addition, the filter hook abutting the inferior vena cava wall and long indwelling time may complicate retrieval. The vena cava diameter is also closely related to the degree of filter tilt.

Inferior Vena Cava Filters and Complications: A Systematic Review

Inferior vena cava (IVC) filters have been used since the 1960s to treat patients with acute risk of pulmonary embolism (PE) to prevent migration of thrombus by trapping it within the filter. Traditional usage has been in patients with contraindication to anticoagulation that carry a significant mortality risk. In this systematic review, we sought to evaluate complications associated with placement of inferior vena cava filters based on published data from the past 20 years. A search was performed on October 6th, 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, using three databases (ProQuest, PubMed and ScienceDirect) for articles published between the dates of February 1, 2002 and October 1, 2022. Results were filtered to include full-text, clinical studies, and randomized trials written in English pertaining to keywords "IVC filter AND complications", "Inferior Vena Cava Filter AND complications", "IVC filter AND thrombosis" and "Inferior Vena Cava Filter AND thrombosis". Articles identified by the three databases were pooled and further screened for relevance based on inclusion and exclusion criteria. Initial search results yielded 33,265 hits from all three databases combined. Screening criteria were applied, with 7721 results remaining. After further manual screening, including removal of duplicate hits, a total of 117 articles were selected for review. While there are no consensus guidelines for best practice, there is compelling evidence that IVC filters can provide significant protection against PE with minimal complications if the treatment window is appropriate. Increase in the variety of filter models has led to broader availability, but skepticism remains about their efficacy and safety, with ongoing controversy surrounding appropriate indications. Further research is needed to establish clear guidelines on appropriate indications for IVC placement and to determine time course of complications versus benefits for indwelling filters.

Over-the-wire deployment techniques of option elite inferior vena cava filter: 3D printing vena cava phantom study

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Bent stiff-wire technique with transfemoral access had lower filter tilt ratio at Option IVC filter deployment.

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Original push wire with transjugular access had lower filter tilt ratio at Option IVC filter deployment.

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Filter jumping was common using the original push wire with transjugular access.

Purpose

To compare filter tilt and filter jumping during Option inferior vena cava (IVC) filter deployment with 3 different wires techniques using a 3-dimensional (3D) printing vena cava phantom.

Materials and methods

An IVC 3D printed vena cava phantom was made from a healthy young male’s computed tomographic data. Option IVC filters were deployed with 3 different wires: i) original push wire, ii) hydrophilic stiff wire, and iii) bent stiff wire. Right internal jugular and right femoral access were used 5 times with each wire. Filter tilt angle, tilt ratio, jumping, and tip abutment to the IVC wall were analyzed.

Results

The transfemoral approach with original push wire had significantly higher tilt angle than did the transjugular approach (6.1˚ ± 1.9 vs. 3.5˚ ± 1.3, p = 0.04). Mean tilt ratio was significantly lower with the bent wire with transfemoral access (0.49 ± 0.13 vs. 0.78 ± 0.18 [original push-wire] and 0.67 ± 0.08 [stiff wire], p = 0.019). The ratio was lower also with original push wire with transjugular access (0.34 ± 0.19 vs. 0.57 ±0.11 [stiff wire] and 0.58 ±0.17 [bent wire], p = 0.045). Filter jumping occurred more often with the transjugular approach with original push wire than with stiff or bent-wire delivery. Filter tip abutment to the IVC wall occurred only with the transfemoral approach.

Conclusions

Bent wire with transfemoral access and original push wire with transjugular access had lower filter tilt ratio at Option IVC filter deployment. However, filter jumping was common using the original push wire with transjugular access.

Femoral versus jugular access for Denali Vena Cava Filter placement: Analysis of fluoroscopic time, filter tilt and retrieval outcomes

PURPOSE

To analyze relevant metrics involved in Denali Vena Cava Filter placement via different venous access sites.

MATERIALS AND METHODS

Patients with Denali filters inserted between March 2017 and February 2018 were retrospectively analyzed. Pre-procedural and pre-retrieval computed tomography (CT) were reviewed. We compared inferior vena cava (IVC) diameter, filter tilt angle, filter tip IVC wall abutment, fluoroscopy time, and retrieval outcomes by venous access site. Filter tip abutment/limb penetration and procedure-related complications were investigated.

RESULTS

Seventy-eight patients had successfully-placed Denali filters. Seventy-one of 78 (91%) patients had both pre-procedural and pre-retrieval CT. The majority (35 [49%]) were placed via the right femoral vein (left femoral vein: 22 [31%]; right internal jugular vein: 14 [20%]). The jugular approach involved a longer fluoroscopy time (mean 117 ± 37 s [s]) than the right and left femoral approaches (mean 64 ± 21 s, mean 67 ± 15 s, respectively [p < 0.05]). Filter tilt and filter tip abutment were not significantly different between the 3 access routes. Filter tip abutment and limb penetration were observed in 8/71 (11%) and 2/71 (3%) patients, respectively. Filter retrieval was attempted in 68 of 78 (87%) cases, and all filters were successfully retrieved. One filter arm fractured during advanced retrieval; no other procedure related complications were recorded.

CONCLUSIONS

Both femoral venous approaches can be safely used for placement of the Denali filter. Femoral venous access involved a shorter fluoroscopy time without any differences in filter tilt and filter tip abutment compared to transjugular access.

Filter tilting and retrievability of the Celect and Denali inferior vena cava filters using propensity score-matching analysis

Purpose

To assess the filter tilting and outcomes of the Celect and Denali inferior vena cava (IVC) filters by using a propensity score-matching analysis.

Materials and methods

From January 2009 to November 2017, 181 Celect and 58 Denali filters were inserted in our institution. To assess filter tilt, filter tip abutment or penetration of the IVC wall, and retrieval outcome, independent variables, including age, sex, IVC long diameter, IVC angulation, and proximity of the filter to renal vein insertion, were entered in the propensity model. Comparative analyses were performed before and after propensity score-matching analysis.

Results

Thirty-one patients were enrolled in each group for the final propensity score-matching analysis. The mean filter indwelling time was not significantly different between the groups (26 ± 22 days in Celect and 27 ± 23 days in Denali). After propensity score adjustment, the mean degree of filter tilt was higher in the Celect group (9.5° ± 7.4° vs 5.6° ± 6.7°). Filter tip abutment or penetration of the IVC wall was more common in the Celect group (39% [12/31, abutment: 12, penetration: 0] vs 13% [4/31, abutment: 3, penetration: 1]). The retrieval outcomes were not significantly different before and after propensity score adjustment in both filters.

Conclusion

The Denali IVC filter showed less tilt and low rate of filter tip abutment to the IVC wall after propensity score-matching analysis. The retrieval rate was not significantly different in the short-term filter indwelling setting. More large-scale, long-term follow-up studies are needed to verify these results.

Medical literature, vena cava filters and evidence of efficacy

Up to 15% of all patients with venous thromboembolism (VTE) receive an inferior vena cava filter, and prophylactic placements are increasing. To determine whether current use of filters is based on robust evidence, a global review of the recent (2001–2012) literature on filters was undertaken. The MEDLINE database was searched for articles related to filters appearing during the period 2001–2012, updating a prior search of literature from 1975–2001. All retrieved articles were analysed, classified into predetermined categories and compared to the prior analysis; randomised and large (>100 patients with a filter) comparative non-randomised clinical studies were read in full. The 651 articles, vs 568 in the period 1975–2000, consisted mainly of retrospective series (37.8%), case reports (31.7%), reviews (14.7%, vs 6.7%, p<0.001), animal and/or in vitro studies (7.5%, vs 12.9%, p=0.002), and prospective series or trials (4.9%, vs 7.4%, p=0.07). Of 4 new randomised trials (RCT), none were designed to test the efficacy of the device; to date, only one RCT has attempted to ascertain efficacy, occurring during the period 1975–2000. Eleven large non-randomised studies compared clinical outcomes of patients with and without filters, in VTE patients (n=5) or prophylactic indications (n=6); two studies found statistically significant relationships between filter use and lower mortality rates, though none could demonstrate a causal relationship. Hence, the plethoric literature on filters parallels growing experience with these devices, but still fails to provide reliable evidence that filter use improves relevant clinical outcomes. No indication for filter placement is based on appropriate scientific evidence.

Evidence-Based Evaluation of Inferior Vena Cava Filter Complications Based on Filter Type

Many inferior vena cava (IVC) filter types, along with their specific risks and complications, are not recognized. The purpose of this study was to evaluate the various FDA-approved IVC filter types to determine device-specific risks, as a way to help identify patients who may benefit from ongoing follow-up versus prompt filter retrieval. An evidence-based electronic search (FDA Premarket Notification, MEDLINE, FDA MAUDE) was performed to identify all IVC filter types and device-specific complications from 1980 to 2014. Twenty-three IVC filter types (14 retrievable, 9 permanent) were identified. The devices were categorized as follows: conical (n = 14), conical with umbrella (n = 1), conical with cylindrical element (n = 2), biconical with cylindrical element (n = 2), helical (n = 1), spiral (n = 1), and complex (n = 1). Purely conical filters were associated with the highest reported risks of penetration (90-100%). Filters with cylindrical or umbrella elements were associated with the highest reported risk of IVC thrombosis (30-50%). Conical Bard filters were associated with the highest reported risks of fracture (40%). The various FDA-approved IVC filter types were evaluated for device-specific complications based on best current evidence. This information can be used to guide and optimize clinical management in patients with indwelling IVC filters.

Introducer curving technique to reduce tilting of transfemoral Gunther Tulip IVC filter: in vitro study

BACKGROUND

Severe tilting of Günther Tulip filter (GTF) may be associated with difficulty in retrieval.

PURPOSE

To determine if an introducer curving technique of GTF can decrease the tilting degree of GTF in a caval model.

MATERIAL AND METHODS

The model was constructed by placing Dacron grafts in bifurcated glass tubes. The study included three groups: Right Straight Group (G(1)), Left Straight Group (G(2)), and Left Curved Group (G(3)). In G(3), a 10-20° angle was curved on the metal introducer before insertion to decrease the angle between inferior vena cava axes and metal introducer (A(CM)). Before GTF was released, the distance between the caval right wall and the apical hook (D(CH1)), and A(CM) were measured. The tilt angle of GTF (A(CF)) was also measured.

RESULTS

In G(1), GTF apex tended to center compared to G(2) (59% vs. 36%, P < 0.01). In G(3), GTF apex tended to center compared to G(2) (71% vs. 36%, P < 0.01). The differences of A(CF) between G(1) and G(2) (2.66 ± 1.80 vs. 4.13 ± 2.07, P < 0.01) and between G(2) and G(3) (4.13 ± 2.07 vs. 2.39 ± 1.79, P < 0.01) were statistically significant. There were significant positive correlations between A(CM) and A(CF), whereas significant negative correlations were detected between D(CH1) and A(CF) in each group.

CONCLUSION

The oblique course of GTF delivery system relative to the axis of the cava causes filter tilt, and thus, curving the introducer prior to its introduction helps to reduce the filter tilt. We recommend a clinical study to determine whether the introducer curving technique improves filter centering and its retrievability.