Complications of inferior vena cava filters

Retrieval of a Greenfield Inferior Vena Cava Filter Indwelling for 29 Years

Inferior vena cava (IVC) filters are used to prevent fatal and nonfatal pulmonary embolism in patients who otherwise cannot receive anticoagulation for venous thrombosis. While generally safe and effective, complications can arise, especially after prolonged implantation. Timely retrieval is essential once the indication for insertion has resolved. However, encountering patients with long-standing embedded filters is not uncommon. This case report discusses the successful retrieval of a permanent Greenfield IVC filter after 29 years.

Luminal Changes in Patients with Inferior Vena Cava Filters and Development of Chronic Venous Disease

BACKGROUND

This study aimed to analyze the luminal changes in the iliocaval veins and their effects on the development of signs and symptoms of chronic venous disease manifesting from inferior vena cava (IVC) filter placement.

METHODS

This was a retrospective observations study; deidentified patients with an IVC filter placed with subsequent luminal changes were included. All patients had a computerized tomography (CT) scan with or without ultrasound and those who underwent an intervention for the obstruction had also venography and intravascular ultrasound (IVUS). The diameter of IVC and iliac veins was measured from the near wall to the far wall. IVC diameters measured less than 12 mm were considered to be retractions. Signs and symptoms of chronic venous disease were obtained from patient charts and were reported according to the highest CEAP class. The data were analyzed using descriptive statistics, presenting diameter changes as a mean with standard deviation and a range of diameters included.

RESULTS

Overall, 76 patients were included in this study, of whom 66 had occlusion of the IVC or the Iliac veins. Luminal changes of the IVC were observed in all patients. A total of 58 patients presented with chronic post-thrombotic changes in both the IVC and iliac veins. There were 4 patients that had a luminal reduction with no filling defects or post-thrombotic changes. Average IVC diameter and iliac vein diameter was measured to be 8.3 ± 1.4 mm and 4.6 ± 1.4 mm, respectively. Patients most frequently presented with extremity swelling, but other signs such as venous ulceration or skin damage were observed.

CONCLUSIONS

Permanent luminal changes of the IVC and iliac veins were observed as a result of IVC filter placement and such patients commonly present with signs and symptoms of chronic venous disease. Together, with other known filter complications, these observations add more reasons for a timely retrieval. When such changes occur, patients' appropriate symptoms can be successfully treated. The permanent changes made by filter placement in the IVC and iliac veins further support filter retrieval in a timely fashion. The luminal changes induced by filter placement should be recognized early, particularly in symptomatic patients who can be safely treated with endovenous procedures.

Imaging of Visceral Vessels

The visceral vasculature is inextricably intertwined with abdominopelvic disease staging, spread, and management in routine and emergent cases. Comprehensive evaluation requires specialized imaging techniques for abnormality detection and characterization. Vascular pathology is often encountered on nondedicated routine imaging examinations, which may obscure, mimic, or confound many vascular diagnoses. This review highlights normal arterial, portal venous, and systemic venous anatomy and clinically relevant variants; diagnostic pitfalls related to image-acquisition technique and disease mimics; and characteristics of common and rare vascular diseases to empower radiologists to confidently interpret the vascular findings and avoid misdiagnosis.

Laparoscopic-assisted retrieval of inferior vena cava filter: A case report and literature review

BACKGROUND

The retrieval of inferior vena cava filters beyond the retrieval window poses challenges, requiring alternative techniques.

OBJECTIVES

To discuss the laparoscopy-assisted retrieval approach for difficult inferior vena cava filters.

RESEARCH DESIGN

Case report.

SUBJECTS

A 57-year-old male with a retrievable inferior vena cava filter placed 8 months prior.

MEASURES

Laparoscopy-assisted retrieval technique utilized after unsuccessful interventional attempts.

RESULTS

Successful retrieval of the filter despite thickened intimal tissue involvement, with no postoperative complications.

CONCLUSIONS

Laparoscopy-assisted retrieval offers a direct visual approach for challenging filter removal, proving minimally invasive, safe, and effective.

Venous Thromboembolism: Review of Clinical Challenges, Biology, Assessment, Treatment, and Modeling

Venous thromboembolism (VTE) is a massive clinical challenge, annually affecting millions of patients globally. VTE is a particularly consequential pathology, as incidence is correlated with extremely common risk factors, and a large cohort of patients experience recurrent VTE after initial intervention. Altered hemodynamics, hypercoagulability, and damaged vascular tissue cause deep-vein thrombosis and pulmonary embolism, the two permutations of VTE. Venous valves have been identified as likely locations for initial blood clot formation, but the exact pathway by which thrombosis occurs in this environment is not entirely clear. Several risk factors are known to increase the likelihood of VTE, particularly those that increase inflammation and coagulability, increase venous resistance, and damage the endothelial lining. While these risk factors are useful as predictive tools, VTE diagnosis prior to presentation of outward symptoms is difficult, chiefly due to challenges in successfully imaging deep-vein thrombi. Clinically, VTE can be managed by anticoagulants or mechanical intervention. Recently, direct oral anticoagulants and catheter-directed thrombolysis have emerged as leading tools in resolution of venous thrombosis. While a satisfactory VTE model has yet to be developed, recent strides have been made in advancing in silico models of venous hemodynamics, hemorheology, fluid-structure interaction, and clot growth. These models are often guided by imaging-informed boundary conditions or inspired by benchtop animal models. These gaps in knowledge are critical targets to address necessary improvements in prediction and diagnosis, clinical management, and VTE experimental and computational models.

Acute caval thrombosis leading to obstructive shock in the early post insertion period of an inferior vena cava filter: a case report and literature review

BACKGROUND

Obstructive shock is extremely rare in clinical practice and is caused by acute blood flow obstruction in the central vessels of either the systemic or pulmonary circulation. Utilizing inferior vena cava filters (IVCFs) to prevent pulmonary embolism (PE) is associated with some potential complications, such as inferior vena cava thrombosis (IVCT). Shock as a direct result of IVCT is rare. We present a case of obstructive shock secondary to extensive IVCT caused by inadequate anticoagulant therapy after the placement of an IVCF.

CASE PRESENTATION

A 63-year-old male patient with a traffic accident injury presented orthopaedic trauma and lower limb deep vein thrombosis (DVT). He experienced sudden and severe abdominal pain with hypotension, tachycardia, tachypnea, oliguria and peripheral oedema 5 days after IVCF placement and 3 days after cessation of anticoagulant therapy. Considering that empirical anti-shock treatment lasted for a while and the curative effect was poor, we finally recognized the affected vessels and focused on the reason for obstructive shock through imaging findings-inferior vena cava thrombosis and occlusion. The shock state immediately resolved after thrombus aspiration. The same type of shock occurred again 6 days later during transfer from the ICU to general wards and the same treatment was administered. The patient recovered smoothly in the later stage, and the postoperative follow-up at 1, 3, and 12 months showed good results.

CONCLUSION

This case alerts clinicians that it is crucial to ensure adequate anticoagulation therapy after IVCF placement, and when a patient presents with symptoms such as hypotension, tachycardia, and lower limb and scrotal oedema postoperatively, immediate consideration should be given to the possibility of obstructive shock, and prompt intervention should be based on the underlying cause.

Predictors of retrieval and long-term mortality in patients treated with inferior vena cava filters

OBJECTIVE

Inferior vena cava filters (VCFs) are a therapeutic resource for the treatment of patients with thromboembolic disease who have a contraindication to full-dose anticoagulation. In the present study, we report the retrieval rate and long-term mortality of patients receiving optional inferior VCFs and identify the predictors for retrieval and all-cause mortality during follow-up.

METHODS

We conducted a retrospective cohort study of 739 consecutive recipients of optional inferior VCFs from January 2002 to December 2021 in two hospitals. Different clinical characteristics and procedure-related variables were included in the analysis. The all-cause mortality rate and retrieval rate and the predictive factors were evaluated using multivariate analysis.

RESULTS

Of the 739 patients, 393 (53%) were women. The mean patient age was 69 ± 15 years. Of the patients, 67% presented with pulmonary thromboembolism and 43% with deep vein thrombosis (DVT). A contraindication to anticoagulation was present for nearly 90% of the patients, mainly (47%) related to the surgical procedure. In addition, 44% of the patients had active cancer. Follow-up data were available for 94% of the patients, with an average follow-up time of 6.08 ± 5.83 years. Long-term mortality was 53%. Cancer (odds ratio [OR], 3.60; 95% confidence interval [CI], 2.22-5.83), age (OR, 1.03; 95% CI, 1.08-1.42), and DVT (OR, 2.01; 95% CI, 1.08-1.42) were identified as independent predictors of mortality. The retrieval rate at follow-up was 33%. The predictors for retrieval included the indication of the filter related to a surgical procedure (OR, 4.85; 95% CI, 2.54-9.59), the absence of cancer (OR, 2.89; 95% CI, 1.45-5.75), and younger age (OR, 0.98; 95% CI, 0.97-0.99).

CONCLUSIONS

High long-term mortality was observed. The predictors of mortality were cancer, older age, and DVT. One third of the filters implanted were retrieved. The predictors for retrieval were a contraindication to surgery-related anticoagulation, the absence of cancer, and younger age.

Oral Rivaroxaban Versus Warfarin After inferior Vena cava Filter Implantation: A Retrospective Cohort Study

OBJECTIVES

To assess the efficacy and safety of rivaroxaban compared to warfarin after inferior vena cava (IVC) filter implantation.

METHOD

This retrospective analysis includes data from 100 patients with deep vein thrombosis (DVT) who underwent IVC filter implantation due to a free-floating thrombus (n = 64), thrombus propagation (n = 8), or acute bleeding (n = 8) on therapeutic anticoagulation, catheter-directed thrombolysis (n = 8), or had previously implanted filter with DVT recurrence. Patients were treated with warfarin (n = 41) or rivaroxaban (n = 59) for 3-12 months. Symptomatic venous thromboembolism (VTE) recurrence and bleeding events were assessed at 12 months follow-up.

RESULTS

Three (7.3%) cases of VTE recurrence without IVC filter occlusion occurred on warfarin and none on rivaroxaban. The only (2.4%) major bleeding occurred on warfarin. Three (5.1%) clinically relevant non-major bleedings were detected on rivaroxaban. No significant differences existed between groups when full and propensity scores matched datasets were compared.

CONCLUSIONS

Rivaroxaban seems not less effective and safe than warfarin after IVC filter implantation.

Imaging of inferior vena cava normal variants, anomalies and pathologies, Part 2: Acquired

The inferior vena cava (IVC) is an uncommon site for primary pathologies and secondary involvement is also infrequent, but involvement of the IVC can often drastically change management. It is therefore important to be cognizant of IVC pathologies. This review discussed common and rare neoplastic and non-neoplastic pathologies of the IVC as well as pathology mimics. Primary and secondary neoplasms can lead to tumour extension or bland thrombus formation and it is often important to distinguish between these two entities. It is also important to be aware of pseudo-lesions for accurate diagnosis. Inferior vena cava filter placement and endovascular treatment of the aorta are commonly performed procedures that can be associated with devastating complications, which are luckily infrequent. The calibre of the IVC also has its own clinical significance. Inferior vena cava pathologies, although rare, have a dramatic impact on the patient's outcome and knowledge of these pathologies is prudent.

Contribution

Understand the principles of IVC imaging, the common as well as the rare primary and secondary IVC tumours, differentiate between tumour thrombus and bland thrombus, and recognise IVC lesion mimics and life-threatening pathologies involving the IVC.

Laser-assisted permanent greenfield filter removal with ileocaval stent reconstruction following filter thrombosis, a case report

Emerging literature supports removal of chronic indwelling IVC filters when they are contributing to complications for a patient and are no longer indicated. We present an interesting case of an elderly patient who had a history of DVT and underwent spinal surgery, which required cessation of his anticoagulation and placement of an IVC filter pre-operatively. Approximately 15 years later the patient presented to our institution with chronic occlusion of his IVC at the level of his filter which had never been removed, with bilateral lower extremity DVT and symptoms of phlegmasia cerulea dolens. Despite a previous unsuccessful attempt at DVT thrombectomy at an outside institution, interventional radiology was consulted, and he subsequently underwent successful laser sheath assisted removal of his 15-year-old permanent Greenfield filter with bilateral lower extremity DVT thrombectomy and venous stenting with significant improvement in his presenting symptoms. Clinical presentation, diagnostic workup, case findings, and outcomes are described.

Guideline Compliance and Indications for Inferior Vena Cava Filter Placement at a Quaternary Care Medical Center

PURPOSE

This study investigated physician compliance with indications for inferior vena cava (IVC) filter placement according to the 2012 American College of Chest Physicians (ACCP) and the 2011 Society of Interventional Radiology (SIR) guidelines.

MATERIALS AND METHODS

A retrospective medical record review of 231 retrievable IVC filters placed between August 15, 2016, and December 28, 2017, at a large urban academic medical center. Guideline compliance to the 2012 ACCP and the 2011 SIR guidelines, and indications for IVC filter placements were assessed through an adjudication protocol. Filter retrieval and complication rates were also examined.

RESULTS

Compliance to guidelines was low (60.2% for ACCP; 74.0% for SIR), especially for non-intensive care unit (ICU) patients (ICU 74.6% vs non-ICU 54.8%, p=0.007 for ACCP; ICU 82.5% vs non-ICU 70.8%, p=0.092 for SIR). After adjudication, 8.2% (19/231) of filters were considered non-indicated but reasonable, 17.7% (41/231) non-indicated and unreasonable, and 13.9% (32/231) SIR-indicated but not ACCP-indicated. The most common indication was venous thromboembolism with contraindication to anticoagulation. The most common reasons for non-compliance were distal deep venous thrombosis with contraindication to anticoagulation (19/60, 31.6%) and clot burden (19/60, 31.6%). One-year filter retrieval and 90-day complication rates were 32.0% (74/231) and 6.1% (14/231), respectively.

CONCLUSION

Compliance to established guidelines was low. Reasons for non-compliance included limitations or discrepancies in guidelines, as well as non-evidence-based filter placements.

CLINICAL IMPACT

Despite increasing utilization of inferior vena cava (IVC) filters, guideline compliance for IVC filter placement among providers is unclear. The results of this study indicate that physician compliance to established guidelines is poor, especially in non-intensive-care-unit patients. Noncompliance stems from non-evidence-based filter placement as well as differences and limitations in guidelines. Avoiding non-indicated IVC filter placement and consolidation of guidelines may significantly improve guideline compliance. The critical insights gained from this study can help promote judicious use of IVC filters and highlight the role of venous thromboembolism experts in navigating complex cases and nuances of guidelines.

Do Prophylactic Inferior Vena Cava Filters Affect the Rates of Venous Thromboembolism and Pulmonary Embolism in Patients Undergoing Major Spine Surgery?

STUDY DESIGN

Retrospective Analysis.

BACKGROUND

Venous thromboembolism (VTE) represents a significant cause of morbidity and mortality in major spine surgery. Placement of prophylactic inferior vena cava filters (IVCF) in patients undergoing major spine surgery was previously adopted at our institution. This study reports our experience and compares VTE rates between patients with and without preoperative IVCF placement.

METHODS

A Retrospective comparative study was conducted on adult patients who underwent IVCF placement and those who did not prior to their spinal fusion procedure, between 2013 and 2016. Thoracolumbar fusions (anterior and/or posterior) of 7 or more levels, spinal osteotomies, and a minimum of a 3-month follow-up were included. Traumatic, oncologic, and cervical pathology were excluded. Primary outcomes measured included the incidence of overall VTE (DVT/PE), death, IVCF related complications, and IVCF retrieval.

RESULTS

386 patients who underwent major spine surgery, 258 met the eligibility criteria. Of those patients, 105 patients (40.7%) had prophylactic IVCF placement. All patients had postoperative SCDs and chemoprophylaxis. The presence of an IVCF was associated with an increased rate of overall VTE (14.3% vs 6.5%, P ≤ .05) and DVT episodes (8.6% vs 2.6%, P = .04). The rate of PE for the IVCF group and non-IVCF group was 8.6% and 4.6%, respectively, which was not statistically significant (P = .32). The all-cause mortality rate overall of 2.3% was statistically similar between both groups (P = 1.0). The IVCF group had higher rates of hematoma/seroma vs the non-IVCF group (12.4% vs 3.9%, P ≤ .05). 99 IVCFs were retrievable designs, and 85% were successfully retrieved. Overall IVCF-related complication rate was 11%.

CONCLUSIONS

No statistical difference in PE or mortality rates existed between the IVCF and the control group. Patients with IVCF placement experienced approximately twice the rate of VTE and three times the rate of DVT compared to those without IVCF. The IVCF-related complication rate was 11%. Based on the results of this study, the authors recommend against the routine use of prophylactic IVCFs in adults undergoing major spine surgery.

LEVEL OF EVIDENCE

III.

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.

Migrated Inferior Vena Cava (IVC) Filter Presenting as Tricuspid Valve Mass, Right-Sided Heart Failure, and Parodoxical Emboli

A 58-year-old male with an unknown medical history presented with acute encephalopathy, receptive aphasia, and hypertensive emergency. The patient did not have any family members from whom a collateral history could be obtained. He underwent X-rays of the abdomen and bilateral humeri/femurs to check for foreign bodies. He was found to have right femoral open reduction and internal fixation with retained screw fragments. He was diagnosed with ischemic stroke on MRI. Transthoracic echocardiogram (TTE) revealed right-sided heart failure and a tricuspid valve mass as well as right to left shunting. This raised concern for large atrial septal defect (ASD) with paradoxical embolization from tricuspid valve mass. Transesophageal echocardiogram (TEE) redemonstrated large ASD. Concern was raised for the ASD closure device as the cause of this "tricuspid mass." Due to history of orthopedic procedure, it was hypothesized that the patient had an IVC filter placed in the setting of pulmonary embolism (PE) prior to an orthopedic procedure. The tricuspid valve was visualized under fluoroscopy and was confirmed to be a migrated IVC filter. He was taken to the operating room (OR) for cardiac surgery for the removal of the IVC filter and repair of ASD. Surprisingly, no ASD was found.

Which caval diameter? Clarification manufacturer's instructions for inferior vena cava filter use and implications for practice

AIM

To clarify manufacturer's instructions for inferior vena cava (IVC) filter use and implications for practice.

MATERIALS AND METHODS

Three vendors of IVC filters were contacted for clarification, with all stating that caval diameter limits are to be true maximum and true minimum cross-sectional diameters. To determine the implications of this, measurements were performed on 302 abdominal computed tomography studies in four transaxial dimensions perpendicular to the long axis including true maximum and minimum diameters, and measurements reflecting those typically taken on fluoroscopic cavography.

RESULTS

Based on the true maximum and true minimum caval diameter limits as clarified by vendors, 22% of patients who would typically be considered suitable for IVC filter insertion based on frontal and lateral fluoroscopic cavography would be contraindicated, and 40% of patients who would typically be considered suitable for IVC filter insertion based on only frontal fluoroscopic cavography (as lateral projection is often not performed) would be contraindicated.

CONCLUSION

There is a marked discordance between the vendor-clarified caval diameter limits of three common IVC filter devices and real-world caval geometry. Given the rarity of complications, this suggests a pressing need for revision of manufacturers' instructions for use statements to better reflect current safe routine clinical use, particularly from a medicolegal perspective.

Clinical outcomes of AngioJet pharmacomechanical thrombectomy versus catheter-directed thrombolysis for the treatment of filter-related caval thrombosis

BACKGROUND

The inferior vena cava filter is utilized worldwide to intercept thrombi and to reduce the risk of fatal pulmonary embolism (PE). However, filter-related thrombosis is a complication of filter implantation. Endovascular methods such as AngioJet rheolytic thrombectomy (ART) and catheter-directed thrombolysis (CDT) can treat filter-related caval thrombosis, but the clinical outcomes of both treatment modalities have not been determined.

AIM

To compare the treatment outcomes of AngioJet rheolytic thrombectomy vs catheter-directed thrombolysis in patients with filter-related caval thrombosis.

METHODS

In this single-center retrospective study, 65 patients (34 males and 31 females; mean age: 59.0 ± 13.43 years) with intrafilter and inferior vena cava thrombosis were enrolled between January 2021 and August 2022. These patients were assigned to either the AngioJet group (n = 44) or the CDT group (n = 21). Clinical data and imaging information were collected. Evaluation measures included thrombus clearance rate, periprocedural complications, urokinase dosage, incidence of PE, limb circumference difference, length of stay, and filter removal rate.

RESULTS

Technical success rates were 100% in the AngioJet and CDT groups. In the AngioJet group, grade II and grade III thrombus clearance was achieved in 26 (59.09%) and 14 (31.82%) patients, respectively. In the CDT group, grade II and grade III thrombus clearance was accomplished in 11 (52.38%) patients and 8 (38.10%) patients, respectively (P > 0.05).The peridiameter difference of the thigh was significantly reduced in patients from both groups after treatment (P < 0.05). The median dosage of urokinase was 0.08 (0.02, 0.25) million U in the AngioJet group and 1.50 (1.17, 1.83) million U in the CDT group (P < 0.05). Minor bleeding was shown in 4 (19.05%) patients in the CDT group, and when it was compared with that in the AngioJet group, the difference was statistically significant (P < 0.05). No major bleeding occurred. Seven (15.91%) patients in the AngioJet group had hemoglobinuria and 1 (4.76%) patient in the CDT group had bacteremia. There were 8 (18.18%) patients with PE in the AngioJet group and 4 (19.05%) patients in the CDT group before the intervention (P > 0.05). Computed tomography angiopulmonography (CTA) showed that PE was resolved after the intervention. New PE occurred in 4 (9.09%) patients in the AngioJet group and in 2 (9.52%) patients in the CDT group after theintervention (P > 0.05). These cases of PE were asymptomatic. The mean length of stay was longer in the CDT group (11.67 ± 5.34 d) than in the AngioJet group (10.64 ± 3.52 d) (P < 0.05). The filter was successfully retrieved in the first phase in 10 (47.62%) patients in the CDT group and in 15 (34.09%) patients in the AngioJet group (P > 0.05).Cumulative removal was accomplished in 17 (80.95%) out of 21 patients in the CDT group and in 42 (95.45%) out of 44 patients in the ART group (P > 0.05). The median indwelling time for patients with successful retrieval was 16 (13139) d in the CDT group and 59 (12231) d in the ART group (P > 0.05).

CONCLUSION

Compared with catheter-directed thrombolysis, AngioJet rheolytic thrombectomy can achieve similar thrombus clearance effects, improve the filter retrieval rate, reduce the urokinase dosage and lower the risk of bleeding events in patients with filter-related caval thrombosis.

Retrieval of a Cook Celect inferior vena cava (IVC) filter after prolonged dwell time of 5,117 days: Factors to consider for retrieval of long-dwell IVC filters

Inferior vena cava (IVC) filters are used in certain patients to help prevent the occurrence of pulmonary embolism (PE). IVC filters are generally recommended to be removed once PE prophylaxis is no longer required. Long-dwelling IVC filters are associated with higher complication rates (Vasa 2020; 49: 449), being more difficult to retrieve and associated with higher retrieval complications (Cardiovasc Diagn Ther 2016; 6: 632). This report describes the pre-procedural work-up and removal of an IVC filter with a prolonged dwell time of 5,117 days (14 years, 3 days) using the loop snare advanced retrieval technique. As far as the authors are aware this case is the longest-described successful retrieval of a Cook Celect IVC filter at 5,117 days.

Improving the rate of inferior vena cava filter retrieval through multidisciplinary engagement

Background

The placement of retrievable inferior vena cava (IVC) filters occurs commonly, but retrieval rates remain low. Consequently, there is an unmet clinical need to ensure appropriate follow-up and retrieval of these devices.

Objectives

To determine the association between an IVC filter surveillance team with filter retrievals or a documented filter plan, time to retrieval, and incidence of filter complications or recurrent venous thromboembolism.

Methods

Ambidirectional cohort study evaluating consecutive IVC filter insertions before and after the implementation of a multidisciplinary surveillance team (MDST). We report an odds ratio (OR) with 95% CIs, adjusted by age, sex, weight, and malignancy status.

Results

Overall, 453 patients were included, with 272 individuals in the pre-MDST cohort and 181 individuals in the post-MDST cohort. The MDST was associated with a higher composite primary outcome of IVC filter retrieval or a documented filter plan from 79.4% in the pre-MDST cohort to 96.1% in the post-MDST cohort (OR, 6.44; 95% CI, 3.06-15.84). Compared with the pre-MDST cohort, IVC filter retrieval rates were higher in the post-MDST cohort (52.6%-73.5%, respectively; (OR, 2.50; 95% CI, 1.67-3.78). The MDST was associated with a shorter median time-to-filter retrieval (187-150 days, hazard ratio, 1.78; 95% CI, 1.39-2.29), but there was no significant difference when comparing symptomatic or clinically significant IVC filter complications, recurrent venous thromboembolism, or mortality.

Conclusion

Our study demonstrates the importance of a structured program to ensure timely IVC filter retrieval and ultimately improve patient care.

Metal in motion: a case report of inferior vena cava filter migration

Background

Inferior vena cava (IVC) filter migration, particularly to the heart, is a rare complication. Small metal fragments may be inadequately characterized on transthoracic echocardiography and may be missed entirely on chest radiograph. Managing the adverse outcomes of IVC filters is a formidable challenge as retrieval carries the risk of arrhythmia, right ventricular perforation, and damage to the tricuspid valve.

Case summary

A woman in her fifties underwent routine computed tomography (CT) calcium score screening and was found to have a metallic fragment in the right ventricle of her heart. Subsequent contrast enhanced, ECG-gated cardiac CTA was completed and images were reconstructed to yield cine images on syngo.via (Siemens, Erlangen, Germany) and vitrea workstation (version: 6.6.3; Vital, Toshiba Medical Systems) to guide heart team discussion and clinical management.

Discussion

Our case illustrates the benefit of CTA with cineography in characterizing the location, size, and extent of fragment involvement within the myocardium. Moreover, this case serves as a reminder to medical professionals to carefully consider IVC filter placement in the appropriate patient, remain vigilant regarding potential complications, and to aspire follow-up of removable filters.

Removal of inferior vena cava filter by open surgery after failure of endovenous retrieval

Background

The permanent placement of inferior vena cava (IVC) filters may lead to numerous complications and their removal is recommended once the risk of pulmonary embolism is reduced. Removal of IVC filters by endovenous means is preferred. But failure of endovenous removal happens when recycling hooks penetrate the vein wall and filters are left in place for too long time. In these scenarios, open surgery may be effective for removal of IVC filters. We aimed to describe the surgical approach, outcomes, and 6-month follow-up of the removal of IVC filter by open surgery, after the failure of removal via the endovenous method.

Methods

A total of 1,285 patients with retrievable IVC filters were admitted from July 2019 to June 2021, including 1,176 (91.5%) endovenous filter removals, and 24 (1.9%) open surgical IVC filter removals after the failure by endovenous method, of whom 21 (1.6%) were followed-up and eligible for analysis of the study. Patient characteristics, filter type, filter removal rate, IVC patency rate, and complications were retrospectively analyzed.

Results

Twenty-one patients were left with IVC filters for 26 (10, 37) months, of which 17 (81.0%) patients had non-conical filters and 4 (19.0%) had conical filters; all 21 filters were successfully removed, with a 100% removal rate, no deaths, no serious complications, and no symptomatic pulmonary embolism. At the 3rd month follow-up after surgery and 3rd month follow-up after discontinuation of anticoagulation therapy, only 1 case (4.8%) had IVC occlusion, but without any occurrence of new lower limb deep venous thrombosis and silent pulmonary embolism.

Conclusion

Open surgery can be used for the removal of IVC filters after failure of removal by endovenous method or when accompanied by complications without symptoms of pulmonary embolism. Open surgical approach can be used as an adjunctive clinical intervention for the removal of such filters.

Placement and retrieval of bilateral iliac vein filters in patients with mega cava

Temporary interruption of the inferior vena cava is the recommended treatment to prevent pulmonary embolism in patients with venous thromboembolism (VTE) and active contraindications for therapeutic anticoagulation. In patients with mega cava (diameter >30 mm), temporary inferior vena cava filters are contraindicated. In the present report, we have described the successful placement and retrieval of bilateral iliac vein filters in two patients with VTE, mega cava, and active contraindications for therapeutic anticoagulation. At the last follow-up, both patients had recovered without recurrent VTE and had had all filters successfully retrieved without complications.

Catheter-Directed Interventions for the Treatment of Lower Extremity Deep Vein Thrombosis

Lower extremity deep vein thrombosis (DVT) leads to significant morbidity including pain, swelling, and difficulty walking in the affected limb. If left untreated, DVT increases the risk of pulmonary embolism (PE), recurrent venous thromboembolism (VTE), and post thrombotic syndrome (PTS). The objective of this review was to identify catheter-directed interventions and their success rates for the treatment of lower extremity DVT. A comprehensive search of current and emerging catheter-directed interventions for lower extremity DVT treatment was conducted in PubMed and Google Scholar. Clinical trials, retrospective and prospective observational studies, and case reports were identified to classify percutaneous mechanical thrombectomy (PMT), catheter-directed thrombolysis (CDT), and pharmacomechanical CDT (PCDT) devices based on their mechanism of action and indication of use. Catheter-directed interventions such as PMT, CDT, and PCDT offer an alternative therapeutic strategy for DVT management, particularly in patients with limb-threatening conditions and absolute contraindications to anticoagulants. Currently, there are limited guidelines for the use of mechanical and pharmacomechanical devices because of the lack of clinical evidence available for their use in treatment. Future studies are required to determine the short and long-term effects of using catheter-directed interventions as well as their effectiveness in treating acute versus subacute and chronic DVT.

The application of inferior vena cava filters in orthopaedics and current research advances

Deep vein thrombosis is a common clinical peripheral vascular disease that occurs frequently in orthopaedic patients and may lead to pulmonary embolism (PE) if the thrombus is dislodged. pulmonary embolism can be prevented by placing an inferior vena cava filter (IVCF) to intercept the dislodged thrombus. Thus, IVCFs play an important role in orthopaedics. However, the occurrence of complications after inferior vena cava filter placement, particularly recurrent thromboembolism, makes it necessary to carefully assess the risk-benefit of filter placement. There is no accepted statement as to whether IVCF should be placed in orthopaedic patients. Based on the problems currently displayed in the use of IVCFs, an ideal IVCF is proposed that does not affect the vessel wall and haemodynamics and intercepts thrombi well. The biodegradable filters that currently exist come close to the description of an ideal filter that can reduce the occurrence of various complications. Currently available biodegradable IVCFs consist of various organic polymeric materials. Biodegradable metals have shown good performance in making biodegradable IVCFs. However, among the available experimental studies on degradable filters, there are no experimental studies on filters made of degradable metals. This article reviews the use of IVCFs in orthopaedics, the current status of filters and the progress of research into biodegradable vena cava filters and suggests possible future developments based on the published literature by an electronic search of PubMed and Medline databases for articles related to IVCFs searchable by October 2022 and a manual search for citations to relevant studies.

Case report: Endoluminal removal of a retrievable conical inferior vena cava filter with a ruptured retraction hook attached to the wall

We report the case of a patient who underwent endovascular retrieval of a conical inferior vena cava (IVC) filter with a ruptured retraction hook that was attached to the IVC wall. A 21-year-old woman with a Celect (Cook) filter, implanted 1,522 days prior, requested retrieval. Preoperative ultrasound and CT examinations showed that the filter was inclined, the retraction hook was attached to the IVC wall, and one of the filter’s pedicles was broken. The inferior vena cava was patent, with no thrombus. Old superficial femoral vein thrombosis could be seen in the right lower extremity. The filter retrieval equipment (Gunther Tulip, Cook) failed to capture the retraction hook. By means of a pigtail catheter (with a partly removed catheter tip) and loach guidewire, we applied a modified loop-snare technique to successfully cut the proliferative tissue near the tip of the retraction hook, by which the hook re-entered the inferior vena cava. Although the snare successfully captured the retraction hook and retrieved the filter, the broken pedicle was retained in the inferior vena cava. We used forceps to capture and pull it to the distal end. In the end, the inferior vena cava became patent, with no contrast agent spillage or residual, and no symptomatic pulmonary embolization. A simultaneous occurrence of oblique adherence and fracture is rarely found in the same filter; however, by using the modified loop-snare technique and biopsy forceps technique, we successfully retrieved the filter and broken pedicle. Our case provides a practical auxiliary technique for regular clinical practice.

Inferior Vena Cava Filter Litigation Review: An Analysis of Medicolegal Cases Pertaining to Inferior Vena Cava Filters

PURPOSE

To identify and analyze all medical malpractice and product liability lawsuits pertaining to inferior vena cava (IVC) filters published within a well-recognized legal research database.

MATERIALS AND METHODS

LexisNexis, a legal research database, was used to retrieve cases that mentioned harm from IVC filters, or lack thereof, as the cause for legal action. A total of 672 cases were analyzed for type of case (medical malpractice or product liability), filter model implanted, filter complications, court decisions, and settlement payments if any.

RESULTS

Of 95 analyzed cases, 20 (21.1%) were medical malpractice cases and 75 (78.9%) were product liability cases. C.R. Bard was the manufacturer associated with the most lawsuits (n = 41, 48.8%). The most litigious filters were the G2 filter from C.R. Bard (n = 17, 20.2%) and Greenfield filter from Boston Scientific (n = 17). The most common complications were IVC penetration (n = 26, 29.9%), filter migration (n = 26, 29.9%), filter fracture (n = 23, 26.4%), and tilt (n = 16, 18.4%). The number of product liability cases has increased from accounting for 25.0% (2 of 8) of filter lawsuits between 2000 and 2010 to 83.9% (73 of 87) during 2011-2020. Of the 20 medical malpractice claims, 9 (45%) were filed for failure to place a filter. One physician was found liable for filter-related complications by a state court in 2014.

CONCLUSIONS

The majority of recent IVC filter-related lawsuits are filed against manufacturers on the basis of product liability claims, with the main litigious filters being the G2 and Greenfield filters. Most cases resulted in rulings for physicians or manufacturers. Some were filed against physicians for filter-related complications or for failure to place an IVC filter.

Application of Deep Learning to IVC Filter Detection from CT Scans

IVC filters (IVCF) perform an important function in select patients that have venous blood clots. However, they are usually intended to be temporary, and significant delay in removal can have negative health consequences for the patient. Currently, all Interventional Radiology (IR) practices are tasked with tracking patients in whom IVCF are placed. Due to their small size and location deep within the abdomen it is common for patients to forget that they have an IVCF. Therefore, there is a significant delay for a new healthcare provider to become aware of the presence of a filter. Patients may have an abdominopelvic CT scan for many reasons and, fortunately, IVCF are clearly visible on these scans. In this research a deep learning model capable of segmenting IVCF from CT scan slices along the axial plane is developed. The model achieved a Dice score of 0.82 for training over 372 CT scan slices. The segmentation model is then integrated with a prediction algorithm capable of flagging an entire CT scan as having IVCF. The prediction algorithm utilizing the segmentation model achieved a 92.22% accuracy at detecting IVCF in the scans.

Outcome of anticoagulation with rivaroxaban in patients with non-retrieved inferior vena cava filters for the prevention of filter thrombosis: a retrospective cohort study

Background

Non-retrieved inferior vena cava filter (IVCF) is associated with some severe complications, such as filter thrombosis. The aim of this retrospective cohort study was to evaluate the outcome of rivaroxaban for the prevention of filter thrombosis in patients with non-retrieved IVCF.

Methods

The study based on the VTE registry databases was limited to patients with non-retrieved IVCF treated at Nanjing Drum Tower Hospital from January 2012 to December 2017. Outcomes included filter thrombosis, total bleeding events, death.

Results

A total of 202 patients were enrolled in the study and divided into rivaroxaban group and warfarin group. Mean follow-up period of the two groups was 57.4 ± 20.8 and 62.2 ± 23.0 months, respectively. In risk factors for VTE, transient factors (P = 0.008) and history of VTE (P = 0.028) were statistically different between the two groups. A total of 13 (6.4%) patients developed filter complications, of which 4 (3.5%) and 5 (5.7%) patients in rivaroxaban group and warfarin group developed filter thrombosis, respectively, without significant difference (P = 0.690). The total bleeding events in rivaroxaban group, including major bleeding and clinically relevant and non-major (CRNM) bleeding, were significantly lower than that in warfarin group (P = 0.005). Adjusting for hypertension, transient risk factors, history of VTE and cancer, no differences in the hazard ratio for outcomes were notable.

Conclusions

It is necessary to perform a concomitant anticoagulation in patients with non-retrieved filters. Rivaroxaban can be an alternative anticoagulant option for the prevention of filter thrombosis.

A retrospective cohort study assessing the incidence of inferior vena cava (IVC) occlusion following prophylactic IVC filter insertion: Is anticoagulation necessary during filter dwell?

BACKGROUND

Inferior vena cava (IVC) filters play a role in preventing venous thromboembolism after major trauma where deep venous thrombosis (DVT) risk is up to 80%. It has been suggested that IVC filters are thrombogenic and many patients are therefore placed on therapeutic anticoagulation during IVC filter dwell citing concern of in situ IVC thrombosis, even in the absence of existing DVT.

METHODS

Between 1 June 2018 and 31 December 2021, this retrospective study assessed the incidence of IVC thrombosis following prophylactic IVC filter insertion. Groups were defined according to the presence or absence of therapeutic anticoagulation during filter dwell. The primary outcome was the presence or absence of IVC thrombus at retrieval.

RESULTS

A total of 124 patients were included. Anticoagulation was prescribed in 29 and anticoagulation was not prescribed in 63. A further 32 patients developed a new thrombosis episode after the prophylactic IVC filter was placed, and 29 were prescribed anticoagulation part-way during filter dwell as a result of this diagnosis. No cases of IVC occlusion were observed in any patient group.

CONCLUSIONS

Caval thrombosis was not observed after prophylactic filter placement, with or without the prescription of anticoagulation. While prospective trials are needed to increase the level of evidence, based on these results the use of therapeutic anticoagulation during IVC filter dwell should not be dictated by the presence of an IVC filter alone but rather by the presence of a related thrombosis event.

Complex filter removal using forceps from combined transfemoral and transjugular approach unhooking the filter apex using forceps and dual access: Two case reports

Modern inferior vena cava filters (IVCFs) are intended to be retrieved once a thrombotic process or risk of pulmonary embolism has resolved independent of administration of anticoagulation. IVCF removal can be challenging with the risk of complications including venous perforation, filter migration, and device fracture. IVCF removal has been described using the nomenclature of routine versus advanced retrieval. Routine retrieval is defined as accessing the filter hook with a loop snare device before advancing a sheath over the filter. Advanced retrieval techniques are employed when routine retrieval fails and can refer to a variety of approaches, including filter realignment with loop snare, stiff wire-displacement, use of a wire and snare with dual access, angioplasty balloon advanced over a guidewire, single access sling approach, the sandwich technique, the endobronchial forceps dissection and removal, photothermic ablation with excimer laser, and the filter eversion technique among others. Successful routine retrieval of IVCF has been reported at 74% and IVCF retrieval with advanced techniques has a success rate of nearly 95%. The complication rate with advanced techniques is higher when compared with routine techniques (5.3% vs. 0.4%; p < .05) and, as expected, requires fluoroscopic time. We report two cases of advanced filter retrieval using endobronchial forceps simultaneously or sequentially through the transfemoral and trans-jugular approach.

Acute Deep Vein Thrombosis Involving the Inferior Vena Cava: Interventional Perspectives

Extension of an iliofemoral thrombosis into the inferior vena cava (IVC), or from the IVC descending into the iliofemoral segments, can confer significant morbidity and mortality. Interventional management of acute deep vein thrombosis (DVT) has been controversial, but there is little doubt that certain subpopulations benefit, such as those with symptomatic IVC thrombosis. When considering an intervention, caval involvement introduces technical difficulties due to its larger diameter, high thrombus burden, bilateral limb clot extension and need for dual access. The frequent coexistence of an IVC filter increases the complexity even more. This review summarises the current indications and treatment modalities available for the management of acute DVT involving the vena cava.

Factors Associated With Inferior Vena Cava Filter Placement and Retrieval for Patients With Cancer-Associated Thrombosis

BACKGROUND

Venous thromboembolism is a leading cause of death in patients with cancer. Inferior vena cava filters are utilized to mitigate the risk of pulmonary embolism for patients who have contraindication to, or failure of, anticoagulation.

METHODS

We reviewed an insurance claims database to identify adults receiving cancer-directed therapy and had a new diagnosis of venous thromboembolism. We then evaluated clinical and sociodemographic characteristics in patients with and without filter placement and retrieval.

RESULTS

There were 25,788 patients (mean [SD] age: 68.3 [12.7] years) who met the study inclusion criteria, with 2111 individuals (8.2%) undergoing filter placement. Filter placement was associated with the type of thrombosis, malignancy, recent surgery, comorbidities, and income. A total of 137 patients (6.5%) newly started anticoagulation within 3 days of filter placement, and 612 (29%) patients received anticoagulation within 30 days after filter placement. Despite this, only 159 (7.5%) patients had their filters retrieved during the study period. Patients with income of $75-99K (odds ratio 2.13, P = .012) or above $100K (odds ratio 1.8, P = .038) were more likely to have filter retrieval compared with those with income <$50K. Filter retrieval was also more likely in younger patients and those with fewer comorbidities or without central nervous system or lung malignancies.

CONCLUSIONS

Inferior vena cava filter placement and retrieval are associated with several sociodemographic factors. Filter retrieval rates are low despite re-initiation of anticoagulation in many patients. Efforts are needed to address disparities in filter use and improve retrieval rates.

Vena Cava Filters: Toward Optimal Strategies for Filter Retrieval and Patients' Follow-Up

Mortality rates associated with venous thromboembolism (VTE) are high. Inferior vena cava filters (IVCFs) have been frequently placed for these patients as part of their treatment, albeit the paucity of data showing their ultimate efficacy and potential risk of complications. Issues regarding long-term filter dwell time are accounted for in society guidelines. This topic has led to an FDA mandate for filter retrieved as soon as protection from pulmonary embolism is no longer needed. However, even though most are retrievable, some were inadvertently left as permanent, which carries an incremental lifetime risk to the patient. In the past decade, attempts have aimed to determine the optimal time interval during which filter needs to be removed. In addition, distinct strategies have been implemented to boost retrieval rates. This review discusses current conflicts in indications, the not uncommon complications, the rationale and need for timely retrieval, and different quality improvement strategies to fulfill this aim.

The Good, Bad, and Ugly of Inferior Vena Cava (IVC) Filters: Anesthetic Management for IVC Filter Retrieval in the Setting of Filter Thrombosis

We describe a case of a 58-year-old man presenting to the interventional radiology (IR) suite for inferior vena cava (IVC) filter retrieval and potential intravascular iliocaval stent reconstruction in the setting of anticoagulation and uncontrolled hypertension. This patient had recently undergone iliocaval thrombectomy with IVC venoplasty four weeks prior to presentation. Induction of anesthesia and endotracheal intubation occurred without complication. The patient received two large-bore intravenous (IV) catheters and a radial artery catheter for hemodynamic monitoring. Blood was cross-matched and kept in the IR suite, anticipating bleeding from a potential injury to the IVC during filter retrieval. Fortunately, the thrombosed filter was removed without complication. This case illustrates the importance of in-depth anesthetic planning for so-called “benign” surgical procedures and highlights the challenges faced in non-operating room locations for anesthesiologists.

Mathematical and Computational Modeling of Device-Induced Thrombosis

Given the extensive and routine use of cardiovascular devices, a major limiting factor to their success is the thrombotic rate that occurs. This both poses direct risk to the patient and requires counterbalancing with anticoagulation and other treatment strategies, contributing additional risks. Developing a better understanding of the mechanisms of device-induced thrombosis to aid in device design and medical management of patients is critical to advance the ubiquitous use and durability. Thus, mathematical and computational modelling of device-induced thrombosis has received significant attention recently, but challenges remain. Additional areas that need to be explored include microscopic/macroscopic approaches, reconciling physical and numerical timescales, immune/inflammatory responses, experimental validation, and incorporating pathologies and blood conditions. Addressing these areas will provide engineers and clinicians the tools to provide safe and effective cardiovascular devices.

Pregnancy in women with an inferior vena cava filter: a tertiary center experience and overview of the literature

The risk of pregnancy in women with in situ vena cava filter is unknown and was evaluated in a cohort study and literature.

Only 20 pregnancies were identified; 1 published case with pre-existent filter perforation had uterine trauma and fetal loss.

Patients with an inferior vena cava (IVC) filter that remains in situ encounter a lifelong increased risk of deep vein thrombosis and IVC filter complications including fracture, perforation, and IVC filter thrombotic occlusion. Data on the safety of becoming pregnant with an in situ IVC filter are scarce. The objective was to evaluate the risk of complications of in situ IVC filters during pregnancy. We performed a retrospective cohort study of pregnant patients with an in situ IVC filter from a tertiary center between 2000 and 2020. We collected data on complications of IVC filters and pregnancy outcomes. Additionally, we performed a systematic literature search in MEDLINE, Embase, and gray literature. We identified 7 pregnancies in 4 patients with in situ IVC filters with a mean time since IVC filter insertion of 3 years (range, 1-8). No complications of IVC filter occurred during pregnancy. Review of literature yielded five studies including 13 pregnancies in 9 patients. In 1 pregnancy a pre-existent, until then asymptomatic, chronic perforation of the vena cava wall by the IVC filter caused major bleeding and uterine trauma with fetal loss. Overall, the complication rate was 5%. It seems safe to become pregnant with an indwelling IVC filter that is intact and does not show signs of perforation, but because of the low number of cases, no firm conclusions about safety of in situ IVC filters during pregnancy can be drawn. We suggest imaging before pregnancy to reveal asymptomatic IVC filter complications.

Bidirectional Sling Technique with Biopsy Forceps for Inferior Vena Cava Filter Retrieval

Although the importance of the retrieval of an optional inferior vena cava filter (o-IVCF) has gained attention because of the awareness of a high complication rate with long indwelling time, the o-IVCF retrieval rate remains low. The advanced retrieval technique of o-IVCF may increase the retrieval rate, which in turn diminishes future adverse events. Through two cases, we describe how to perform the novel approach "bidirectional sling technique with biopsy forceps." This technique will improve the retrieval rate in patients following the failure by conventional retrieval technique.

Variability in the perception and application of force used in IVC filter retrievals among interventional radiologists

INTRODUCTION

A long dwell time is associated with higher inferior vena cava (IVC) filter retrieval complication rates. Manufacturers advise that "excessive force should not be used" during filter retrieval; however, the term "excessive" is subjective and is likely to lead to variability amongst operators. The aims of this study were to 1) ascertain what interventional radiologists consider to be excessive force during filter retrieval and 2) to understand the variability in interventional radiologists' perception of force.

METHODS

The authors recruited interventional radiologists to perform a benchtop simulated filter retrieval. Participants were invited to pull on a modified force tester attached to a Gunther Tulip filter retrieval set (GTRS). The participants were asked to pull as if they were retrieving an IVC filter and stop when they felt it was clinically unsafe to apply greater force. They were then asked to replicate forces of 10N and 50N, respectively. Each of the three tasks was completed three times. Data were obtained on the clinical experience of the participants with specific questions focusing on their filter retrieval practices.

RESULTS

The range of maximum forces applied during filter retrieval varied between 0.8 and 79.8N. When asked to replicate 10N and 50N, for attempt-1, the median forces produced were 23.5N and 38.1N, respectively. A trend analysis showed that those who overestimate 10N are more likely to apply a greater overall maximum force (r_s = 0.622; P < 0.001).

CONCLUSION

There is wide variation in what interventional radiologists consider to be the maximum safe force to apply during IVC filter retrieval.

IMPLICATIONS FOR PRACTICE

Manufacturers and operators should consider methods in which only a safe range of forces can be applied during an IVC filter retrieval. Operators may wish to undertake 'personal' force calibration as part of training in interventional radiology.

IVC filter placement in patients undergoing surgical treatment of bone or soft-tissue tumors

BACKGROUND AND OBJECTIVES

Patients with cancer to bone or soft tissues undergoing orthopedic procedures may be unable to receive pharmacologic prophylaxis for venous thromboembolism (VTE). Inferior vena cava (IVC) filters may be an effective method to prevent fatal pulmonary embolism (PE) in these patients.

METHODS

Retrospective chart review performed for patients surgically treated for malignant disease of bone or soft tissue who had IVC filter placement. Type of surgery, anatomic region, and development of wound complications requiring repeat surgery were analyzed.

RESULTS

From 2007 to 2018, 286 patients received IVC filters. Ten (3.5%) patients suffered deep vein thrombus (DVT) postoperatively. There was no acute fatal PE. Two patients suffered PE at 2 and 99 days postoperatively. Risk of DVT was comparable following surgery with endoprosthesis versus open reduction and internal fixation (p = 0.056) and with soft tissue versus bone involvement (p = 0.620). Three filter-related complications occurred. Patients disease at the femur had the highest rate of DVT.

CONCLUSIONS

Following treatment of malignant disease of bone or soft-tissues, two patients with IVC filter placement experienced nonfatal PE and three patients experienced filter-related complications. No patients in this series experienced a fatal PE.

Indications and long-term outcomes of preoperative inferior vena caval filters in 111 patients at high risk of pulmonary embolism undergoing major abdominal surgery

AIMS

Patients with abdominal cancer requiring major surgical intervention are at high risk of venous thromboembolic events (VTE), particularly pulmonary emboli (PE). A proportion of patients with cancer can present with, or have had, major VTEs prior to definitive surgical treatment. Preoperative percutaneous inferior venal caval filters (IVCF) may reduce the risk of PE. The aim of this study was to assess the indications, complications, retrieval rates, and long-term outcome of IVCFs in patients undergoing major abdominal surgery.

METHODS

This was a retrospective analysis of a prospective IVCF database between 2007 and 2018 of all patients with IVCF insertion prior to major abdominal surgery. The indications for an IVCF, procedural complications and surgical interventions were recorded.

RESULTS

Overall, 111 patients had IVCF insertion. IVCF placement failed in one patient with gross abdominal disease. Indications for an IVCF were: prior PE in 65/111 (59%) and major vein thrombus in 42 (38%). Overall, 26/111 (23%) had the IVCF removed at a median of 91 days. In two patients IVCF removal failed. At follow-up of the 85 patients who had the IVCF left in situ, six developed filter-related thrombus and 13 a deep vein thrombosis (DVT). Four patients had a PE with an indwelling IVCF.

CONCLUSION

Preoperative IVCF may reduce perioperative PE in patients at high risk of thrombosis undergoing major abdominal surgery where early anticoagulation is contraindicated. Long-term follow-up of retained IVCF suggests that major problems are infrequent, though further thrombosis may occur and long-term anticoagulation may be needed.

Tine-Based Leadless Pacemaker: Strategies for Safe Implantation in Unconventional Clinical Scenarios

Leadless pacemakers (LPs) have emerged as a meaningful alternative to transvenous pacemakers for single-ventricular pacing. LPs eliminate many of lead- and pocket-associated complications observed with transvenous pacemakers. Owing to the lack of atrioventricular synchronous pacing until recently, the use of LP was generally reserved for those patients who either required minimal ventricular pacing or had permanent atrial fibrillation. The only commercially available LP is the Micra transcatheter pacing system (Micra-TPS, Medtronic Inc. Fridley, Minnesota), which requires insertion of a 27-F (outer diameter) introducer sheath in the femoral vein. The LP is delivered to the right ventricle using a 23-F delivery catheter. Owing to the need for a large-bore sheath, the pivotal studies for the Micra transcatheter pacing system excluded patients with indwelling inferior vena cava filters and included only a few patients with bioprosthetic or repaired tricuspid valve. Subsequent real-world experience has demonstrated the overall safety and feasibility of LP placement, and use in various unconventional clinical settings has been validated, albeit with specific precautions. Additionally, incorporation of adjunctive techniques and strategies can improve the safety of the procedure in routine clinical settings as well. The objective of this state-of-the-art review is to highlight the key procedural elements to facilitate safe and efficient implantation of LP in routine as well as in unique clinical settings.

Prevention of Pulmonary Cement Embolism by Inferior Vena Cava Filter following Vertebroplasty-related Cement Intravasation

A 77 year old woman with recent history of vertebroplasty for treatment of multiple osteoporotic lumbar vertebral body compression fractures presented for post-procedure care. A series of radiographs and cross-sectional imaging of the lumbar spine revealed an unexpected finding of cured bone cement within a small lumbar vertebral vein, the inferior vena cava and within the spokes of an inferior vena cava filter which had originally been placed two years earlier. Inferior vena cava filters have become the standard of care to prevent pulmonary embolism in the setting of deep venous thrombosis. However, cases of foreign materials becoming entrapped in filters are uncommon despite the documented frequency of intravasation of bone cement into the circulatory system following vertebroplasty procedures. This case is significant because it illustrates the rare occurrence of an inferior vena cava filter capturing intravasated bone cement and preventing its migration to the pulmonary circulation.

Impact of Advanced Technique on Improvement in the Retrievable Inferior Vena Cava Filter Retrieval Rate

BACKGROUND

It is recommended to remove retrievable inferior vena cava filters (r-IVCFs) when they are no longer needed because their presence may give rise to serious complications related to prolonged placement of the filter. An advanced filter retrieval technique may help improve the retrieval rate.Methods and Results:107 consecutive patients (mean age; 61±18 years, male 53%) in whom r-IVCF retrieval was attempted were prospectively enrolled between April 2012 and December 2018. The frequently used advanced techniques were sling technique and biopsy forceps dissection technique. Retrieval success was 75% with standard retrieval technique alone; however, the overall retrieval success rate improved to 98% with advanced techniques. We observed few serious complications related to the retrieval procedure. Logistic multivariate analysis identified prolonged indwelling time (P=0.0011) and embedded hook in the caval wall (P=0.0114) as independent predictors, and the cutoff value for the indwelling time for requirement of advanced technique was 80 days.

CONCLUSIONS

Advanced retrieval techniques helped improve the retrieval rate without serious complications. We may need to consider the referral of patients to centers with expertise in advanced retrieval techniques when the indwelling time is >80 days, and pre-retrieval CT image shows a hook embedded in the vessel wall.

Migrated Inferior Vena Cava (IVC) Filter Strut: A Rare Cause of Chronic Distal Pancreatitis with Likely Malignant Transformation

Patient: Female, 44-year-old

Final Diagnosis: Pancreatic adenocarcinoma

Symptoms: Abdominal pain

Medication:—

Clinical Procedure: Neoplasm

Specialty: Surgery

Inferior vena cava filter fracture and migration to the pulmonary artery

Inferior vena cava (IVC) filters provide a safe and effective method for protecting against pulmonary embolisms in patients for whom standard anticoagulation therapy for acute deep vein thrombosis is contraindicated. Common complications of IVC filter placement include erosion through the wall of the vena cava, visceral perforation, and filter thrombosis, obstruction, and migration. In this report, we describe the case of a 60-year-old woman who presented with an IVC filter fracture and subsequent migration of the filter to the lung detected via chest radiography.

Retrieval of Bard Simon Nitinol inferior vena cava filters: Approaches, technical successes, complications, and clinical outcomes

OBJECTIVE

The Simon Nitinol filter is a bi-level filtration device designed for permanent implantation that is no longer commercially available, but may result in similar complications to current commercially available long term indwelling temporary or permanent filters. Complications related to indwelling inferior vena cava filters include inferior vena cava thrombosis, inferior vena cava penetration, filter migration, and filter fracture. There is a paucity of reports describing the technical aspects related to retrieval of Simon Nitinol filters.

MATERIALS AND METHODS

This study consisted of five patients with Simon Nitinol filters and describes the indication for retrieval, the retrieval techniques used to remove the filters, technical success, complications, and clinical course.

RESULTS

The indications for retrieval included: abdominal pain (n = 2; 40%), iliocaval thrombosis (n = 1; 20%), identification of an intracardiac filter fragment (n = 1; 20%), and recurrent venous thromboembolic events (n = 1; 20%). Retrieval techniques included: biopsy forceps (n = 3; 60%), excimer laser extraction sheaths (n = 3; 60%), hangman modified loop snares (n = 3; 60%), rigid endobronchial forceps (n = 2; 40%), and balloon deflection (n = 2; 40%). All filters were successfully retrieved. One patient developed a post-procedural intramuscular hematoma near the site of right internal jugular sheath placement.

CONCLUSIONS

Simon Nitinol filters may be retrieved safely and effectively using advanced inferior vena cava filter retrieval techniques.

Feasibility and optimization of ultra-short echo time MRI for improved imaging of IVC-filters at 3.0 T

PURPOSE

To determine the feasibility of ultra-short echo time (UTE) MRA for assessment of inferior vena cava (IVC) filters and evaluate the impact of different imaging protocols at 3.0 T, using conventional Cartesian MRA (cMRA) as the reference standard.

METHODS

Patients with IVC-filters were recruited for this prospective IRB-approved, HIPAA-compliant study. Subjects underwent contrast-enhanced breath-held and a free-breathing 3D radial acquisition UTE-MRA (bhUTE, fbUTE) at three different flip angles (FA: 10°, 15°, 20°) to optimize T1-weighted image quality. Two radiologists performed a direct comparison consensus reading to assess the optimal FA. Image quality (IQ) of both UTE techniques at the best FA was rated independently on a 4-point Likert scale (0 = non-diagnostic, 3 = excellent) and compared to 3D T1-weighted breath-held cMRA.

RESULTS

Nine subjects were recruited. Low FAs of 10° were rated best for both UTE techniques. fbUTE was excellent (3, IQR: 2; 3) and significantly better for IVC-filter depiction than cMRA (2, IQR: 0.75; 2, p = 0.001) and bhUTE (1.5, IQR: 0.75; 2, p < 0.001). Both UTE techniques showed significantly less filter-related artifacts (fbUTE: 28%, bhUTE: 33%) than cMRA (89%, p = 0.001 and p = 0.002, respectively). However, IQ of bhUTE was generally degraded due to high image noise and low image contrast. IQ of the IVC venogram was best with cMRA. Clinically relevant signal voids were only observed with the cage-shaped OptEase filter.

CONCLUSION

UTE-MRA is feasible at 3.0 T for the assessment of IVC-filters, particularly using a free-breathing protocol. Larger studies are needed to investigate the clinical utility of free-breathing UTE-MRA for assessment of IVC-filter-related complications.

Abdominal and pelvic radiographs of medical devices and materials-Part 1: gastrointestinal and vascular devices and materials

When compared with chest radiographs, medical devices of the abdomen and pelvis are less frequently seen. However, with recent advances in technology the interpreting radiologists are seeing more medical objects on these radiographs. The identification of these devices and materials are crucial for not only enabling the radiologist to understand the underlying background pathology but also for evaluating any related complications. An online survey of literature showed our review article to be the most detailed. In this first part of our two-part series, we discuss about the various gastrointestinal and vascular devices and materials seen on abdominal and pelvic radiographs.

A review of preclinical absorbable inferior vena cava filters

OBJECTIVE

Absorbable inferior vena cava filters (IVCFs) could be more effective and safer than standard IVCFs in theory, as they will self-resorb over time, thus rendering the need for filter retrieval and the risks associated with it unnecessary. This scoping review aims to evaluate the design of current absorbable IVCFs, review the development phase of the absorbable IVCFs, assess the efficacy of the absorbable IVCFs and their complications, and discuss the limitations and areas for future research.

METHODS

MEDLINE, PubMed, and Embase databases were electronically searched and citations of relevant studies manually searched. Study selection and data extraction were performed by two independent reviewers using predetermined criteria and stored on premade proforma, respectively. The risk of bias (RoB) for both in vitro and in vivo studies were performed using established RoB tools.

RESULTS

Eight studies were suitable for inclusion in this scoping review; five were in vivo and three were in vitro studies. No clinical trials were found. The RoB varied from moderate to high for in vivo studies and from low to moderate for in vitro studies. Overall, there was evidence from both in vivo and in vitro studies that absorbable IVCFs were effective in clot capturing and self-resorption and could decrease complications associated with standard IVCFs. However, there was a broad lack of statistical analyses and control groups to determine the significance of these findings.

CONCLUSIONS

Absorbable IVCFs have shown promising features and results in preclinical models. However, significant research needs to be further performed to achieve the ideal characteristics of an absorbable IVCF before the first human trial can be conducted safely.