Venographic Findings at Retrieval of Inferior Vena Cava Filters

Risk factors for inferior vena cava filter thrombosis in traumatic fracture patients with deep venous thrombosis of lower extremity: A single-center experience

OBJECTIVE

To explore the risk factors for inferior vena cava filter (IVCF) thrombus in orthopedic trauma patients who underwent filter placement with ongoing anticoagulation in clinical settings.

METHODS

We retrospectively analyzed clinical data from fracture patients with lower extremity acute deep vein thrombosis (DVT) implanted with an IVCF admitted to Tianjin Hospital from January 2017 to December 2019. Potential risk factors, such as gender, age, diabetes, hypertension, fracture sites, thrombus location, free-floating thrombus, filter type, Injury Severity Score (ISS), and postoperative D-dimer values, were analyzed by the Chi-square test, t-test, logistic regression, and receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 662 patients were included in our study, and filter-related thrombosis was present in 67 (10.1%) patients. No significant differences were observed in age, gender, hypertension, diabetes, fracture site, free-floating thrombus, filter type, indwelling time, and postoperative D-dimer level. Thrombus location and ISS were significantly different (p < 0.05). Popliteal DVT (P-DVT) (odds ratio [OR]: 2.130, p = 0.018) and ISS (OR: 1.135, p = 0.000) were associated with filter thrombus. Patients with P-DVT were prone to a small filter thrombus (OR: 3.231, p = 0.037). From the ROC curve analysis, the diagnostic value of ISS was 24.5 and 26.5 for patients with filter and massive filter thrombus, respectively.

CONCLUSION

Thrombus location and ISS were independent risk factors for filter thrombus in patients with traumatic fractures. P-DVT had a higher potential to result in a small filter thrombus and an ISS value >26.5, which was considered a significant massive filter thrombus predictor.

Removing infrarenal inferior vena cava filters (IVCFs) with thrombus under protection of suprarenal IVCFs: A retrospective study in a single-center institution

To determine feasibility of removing inferior vena cava filters (IVCFs) with massive thrombus (>1*1cm) under protection of suprarenal IVCFs, and evaluate the filter thrombus detachment due to removal. The patients who had massive infrarenal IVCFs thrombus and received retrieval under protection of suprarenal IVCFs were retrospectively reviewed from July 2018 to December 2021. Medical data of them including demographics, filter types, dwell time, management, thrombus detachment was collected, and analyzed. There were 33 patients having massive infrarenal IVCFs thrombus and receiving retrieval under protection of suprarenal IVCFs including 23 males and 10 females with a mean age of 55.30 ± 11.97 (range, 30-85 years). All Infrarenal IVCFs were removed successfully and 29 cases (87.88%) were confirmed detachment of thrombus by cavography including 7 small-size thrombus (<1*1cm) and 22 large-size thrombus (>1*1cm). Twenty-two suprarenal IVCFs trapped large-size thrombus were treated with additional anticoagulation and 21 of them had successful retrievals with additional anticoagulation period of 66.18 ± 43.38 days (range, 9-154 days). The large-size IVCFs thrombus may be break off during retrieval, and IVCFs with large-size thrombus could be removed safely with suprarenal IVCFs protection. The thrombus trapped in filters could be reduced with an additional period of anticoagulation.

Classification System for Inferior Vena Cava (IVC) Appearance Following Percutaneous IVC Filter Retrieval

OBJECTIVE

There is no classification system for describing inferior vena cava (IVC) injuries. The objective of this study was to develop a standardized grading system for venographic appearance of the IVC following percutaneous IVC filter retrieval.

METHODS

A classification system for the appearance of the IVC on cavograms following percutaneous IVC filter removal was developed consisting of two grading elements; luminal characteristics and extravasation. Luminal narrowing from 0% up to 50% from any cause is grade 1; narrowing between 50 and 99% is grade 2; occlusion is grade 3; and avulsion is grade 4. Absence of extravasation is grade A, contained extravasation is grade B, and free extravasation is grade C. This system was then applied retrospectively to pre- and post-IVC filter retrieval cavograms performed at a single institution from October 2004 through February 2019.

RESULTS

546 retrieval attempts were identified with 509 (93.2%) filters successfully retrieved. 449 cases (88.2%) had both pre-retrieval and post-retrieval imaging appropriate for application of the proposed classification system. Inter-rater reliability was 0.972 for luminal characteristics, 0.967 for extravasation, and 0.969 overall. Consensus grading demonstrated a distribution of 97.3% grade 1, 1.3% grade 2, 1.3% grade 3, and 0.0% grade 4 for post-retrieval luminal characteristics. For extravasation classification, 96.4% of the cases were classified as grade A, 2.7% grade B, and 0.9% grade C.

CONCLUSION

A classification system was developed for describing IVC appearance after IVC filter retrieval, and retrospectively validated using a single center dataset.

Multi loop snare technique for difficult inferior vena cava filter retrievals

Introduction

Use of optional vena cava filters has steadily increased. In the majority of cases removal is successful using standard techniques. In cases of tilting and migration of the filter however, more advanced techniques are necessary. The "loop-snare" technique has been described for such cases. Difficulties arise when the loop starts to slip around the legs and arms of the filter.

New technique

We present an improved loop-snare technique which allows to retrieve IVC filters when the simple loop-snare technique fails. We used additional loops, in one case one additional loop in another case two additional loops around the filter tip which allowed successful retrieval. The additional loops were created with a reversed shaped catheter. All guidewires were then engaged with a snare and pulled into a large sheath. The additional loops stabilize the tip and the filter can be pulled into the sheath.

Conclusion

The "multiple-loop-snare" technique is a refinement of the previously described "single loop-snare" technique and can be used when one loop fails.

Inferior vena cava filtration in the management of venous thromboembolism: filtering the data

Venous thromboembolism (VTE) is a common cause of morbidity and mortality. This is especially true for hospitalized patients. Pulmonary embolism (PE) is the leading preventable cause of in-hospital mortality. The preferred method of both treatment and prophylaxis for VTE is anticoagulation. However, in a subset of patients, anticoagulation therapy is contraindicated or ineffective, and these patients often receive an inferior vena cava (IVC) filter. The sole purpose of an IVC filter is prevention of clinically significant PE. IVC filter usage has increased every year, most recently due to the availability of retrievable devices and a relaxation of thresholds for placement. Much of this recent growth has occurred in the trauma patient population given the high potential for VTE and frequent contraindication to anticoagulation. Retrievable filters, which strive to offer the benefits of permanent filters without time-sensitive complications, come with a new set of challenges including methods for filter follow-up and retrieval.

Improving retrieval rates for retrievable inferior vena cava filters

The introduction of retrievable inferior vena cava (IVC) filters was an important step in the evolution of deep vein thrombosis/pulmonary embolism management. Their removability makes them preferred to permanent filters in many cases. IVC filter retrieval often occurs at a suboptimal rate, leading to complications associated with long-term placement. Improving retrievability includes solutions for patients being lost to follow-up, filter malpositioning, need arising for permanent IVC filtration, filtration requiring longer than the filter's window of retrievability, and filter compromise by the presence of a large trapped clot. This review explores these strategies for retrieval in detail in hopes of improving IVC filter retrieval rates.

Retrievability of the Günther Tulip Vena Cava Filter after Dwell Times Longer Than 180 days in Patients With Multiple Trauma

PURPOSE

To evaluate the retrieval feasibility of the Günther Tulip inferior vena cava filter (IVCF) after dwell times >180 days in patients with multiple trauma.

METHODS

A retrospective study was conducted of 117 multiple-trauma patients (70 men; mean age 36 years, range 17 to 64) who underwent prophylactic placement of Günther Tulip retrievable IVCFs between December 1, 2003 and October 1, 2006. Prior to IVCF retrieval, all patients had vena cavography to identify possible IVCF thrombus entrapment. Filter retrieval was performed in the catheterization laboratory under sterile conditions from a right internal jugular vein approach. After IVCF retrieval, repeat vena cavography was performed to evaluate the IVC for contrast extravasation, intraluminal defects, or IVC narrowing.

RESULTS

Twelve (10.3%) filters were not retrieved as the patients died of their injuries (no deaths related to IVCF placement or retrieval). Forty-one (35.0%) filters had dwell times >180 days (mean 261.5 days, range 182-403). Of these, 31 (76%) were uneventfully retrieved; 10 were left in place permanently. Pre-retrieval vena cavography identified filter tilting in 13 filters: 9 had a mild tilt < or =10 degrees, and 4 had severe tilting > or =25 degrees. All of the 10 filters that could not be retrieved were tilted (4 severe and 6 mild). In comparison to the 64 (54.7%) filters in place for <180 days (mean 51 days, range 42-180), 4 (6.2%) could not be retrieved (p = 0.367). No filter had trapped thrombus identified by vena cavography at the time of retrieval. None of the retrieved filters had structural fracture or collapse, and none had migrated. Post-retrieval vena cavograms demonstrated no contrast extravasation, intraluminal defects, or impingement on adjacent organs.

CONCLUSION

If retrieval of a Gunther Tulip filter with an dwell time >180 days is considered, the patient should be ambulatory and a candidate for anticoagulation if indicated; notably, the filter should have a <25 degrees tilt. Under these circumstances, retrieval of the Günther Tulip filter after 180 days of dwell time appears justified and safe.