Percutaneous retrieval of an embolized inferior vena cava filter from the pulmonary artery: a case description

Introduction

Inferior vena cava (IVC) filter is a well-established intervention for patients with venous thromboembolic disease who have contraindications to anticoagulation or for whom therapeutic anticoagulation therapy has failed (1,2). Although generally safe, filter placement is associated with certain complications, such as tilt, migration, and fracture (3).Embolization of an IVC filter into the cardiac chambers or pulmonary arteries is exceedingly rare due to the inherent anchorage provided by the filter hooks. In this report, we present a rare case of IVC filter embolization resulting from incorrect device orientation during deployment and the successful retrieval of the embolized device from the pulmonary artery through the use of percutaneous endovascular techniques. Furthermore, we describe a successful retrieval strategy consisting of a “dual-sheath telescoping technique” supported by an extra stiff guidewire to ensure system stability and precise capture of the device.

Case presentation

A 63-year-old woman experienced swelling and pain in her right lower extremity for 5 days. Color Doppler ultrasound confirmed acute deep vein thrombosis (DVT) of the right lower extremity, involving the right popliteal vein and common femoral vein. In addition, the patient was diagnosed with uremia 3 months prior and was undergoing regular hemodialysis. To mitigate the risk of life-threatening pulmonary embolism secondary to acute deep venous thrombosis, a retrievable IVC filter (Denali; Bard Peripheral Vascular, Inc., Tempe, AZ, USA) was selected for deployment.

Given the presence of acute right lower extremity DVT involving the popliteal and common femoral veins, right femoral vein puncture was considered inadvisable due to the risk of thrombus disruption and potential exacerbation of pulmonary embolism. The left femoral vein approach was therefore selected, which also provided a favorable angulation for IVC venography and filter deployment. Venography of the IVC and bilateral renal veins was performed.

However, during deployment, the IVC filter migrated cranially immediately upon release. Based on the appearance on intraprocedural fluoroscopy and the configuration of the retrieved device, we retrospectively inferred that the filter had been released in an inverted configuration, with the filter apex directed caudally toward the renal veins rather than cephalad as intended. We speculated that malorientation of the delivery system during preparation might have contributed to the inverted release. In this configuration, the anchoring hooks failed to engage the IVC wall, and simultaneous strut entanglement reduced the effective filter diameter, allowing the device to traverse the tricuspid valve complex. Fluoroscopy demonstrated progressive migration of the filter from the IVC to the right ventricle (RV), followed by embolization to the left pulmonary artery (LPA).

Percutaneous retrieval via the femoral vein access was deemed technically feasible as the retrieval hook at the filter apex was oriented proximally toward the main pulmonary artery (Figure 1). To provide sufficient support, an 85-cm 14 F delivery sheath (Shanghai Shape Memory Alloy, Ltd., Shanghai, China) was introduced to the LPA over an extra stiff guidewire (Amplatz, Cook Medical, Bloomington, IN, USA). Subsequently, an 87-cm 10 F delivery sheath (Starway Medical Technology, Inc, Beijing, China) was advanced through the 14 F sheath to the LPA along the extra stiff guidewire. Pulmonary angiography confirmed that the migrated filter was stably located in the LPA and did not compromise the blood flow or cause pulmonary artery injury (Figure 2). To maintain system stability, the extra stiff guidewire was retained in situ. A 15-mm loop snare, loaded within a 125-cm 5 F MPA1 catheter (Cordis Corporation, Miami Lakes, FL, USA), was advanced through the 10 F delivery sheath and navigated alongside the stiff wire toward the proximal LPA. Under the dual support of the telescoping sheaths and the anchoring wire, the MPA1 catheter and loop snare were manipulated to successfully grasp the retrieval hook (Figure 3). Once captured, the 10 F sheath was advanced over the MPA1 catheter to partially collapse the filter frame, followed by the 14 F sheath, which fully encased the filter struts in telescoping fashion. Postretrieval visual inspection confirmed that the retrieved filter remained intact (Figure 4). Final postprocedural pulmonary angiography revealed no signs of pulmonary artery injury or distal thrombosis, confirming a successful retrieval (Figure 5). A new IVC filter was subsequently deployed in the correct position. The patient’s vital signs remained stable throughout the procedure, and she was discharged on postprocedural day 3 following an uneventful recovery. At the 1-month outpatient follow-up visit, the patient denied chest pain, dyspnea, palpitations, syncope, hemoptysis, or recurrent lower-extremity swelling. No procedure-related complications were identified clinically, and no additional cardiopulmonary imaging was performed at this visit.

Figure 1.

Intraprocedural fluoroscopic images demonstrating the embolized IVC filter within the RV and its subsequent migration into the LPA. (A) The filter (white arrow) was observed lodged within the RV, with its apex directed toward the RA. The red arrow highlights entanglement of the filter struts, which appeared crowded and angulated rather than symmetrically splayed. The resulting fusiform profile narrowed the effective filter diameter, allowing the device to traverse the tricuspid valve complex and subsequently embolize to the pulmonary artery. (B) The fluoroscopic image obtained at a different complementary projection confirmed that the filter (white arrow) had remained within the RV. (C) The filter migrated into the LPA. (D) A retrieval catheter was advanced to approach the filter hook in the LPA, and the white arrow indicates the catheter tip approaching the hook. IVC, inferior vena cava; LPA, left pulmonary artery; RA, right atrium; RV, right ventricle.

Figure 2.

Intraprocedural pulmonary angiogram performed after positioning of the delivery sheaths. The embolized IVC filter lodged within the LPA, adjacent to the RA and LV silhouettes. Contrast opacification of the distal LPA branches confirmed preserved antegrade blood flow around the filter, with no angiographic evidence of vessel occlusion, dissection, or extravasation. IVC, inferior vena cava; LPA, left pulmonary artery; LV, left ventricle; RA, right atrium.

Figure 3.

Intraprocedural fluoroscopic images demonstrating capture of the filter hook via a loop snare and advancement of the dual sheath through the coaxial delivery system. (A) After the extra stiff guidewire was retained to stabilize the system, the loop snare (red arrow) was advanced through the inner catheter and opened adjacent to the filter hook, prior to engagement. (B) The loop snare (red arrow) was tightened around the filter hook and visualized as a conjoined structure at the snare-hook interface. The successful mechanical engagement of the hook was confirmed, providing a secure point of traction for subsequent coaxial sheath advancement and stepwise collapse of the filter struts.

Figure 4.

The IVC filter after being completely retrieved and inspected after removal. All filter struts were accounted for and structurally intact, with no evidence of fracture, fragmentation, or missing components, confirming complete and intact removal of the embolized device. IVC, inferior vena cava.

Figure 5.

Final postprocedural pulmonary angiogram. No filling defect, contrast extravasation, dissection, or other angiographic evidence of pulmonary arterial injury was identified, and antegrade flow through the LPA was preserved. LPA, left pulmonary artery.

All procedures described in this study were conducted in accordance with the ethical standards of the relevant institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

Several reasons for IVC filter migration have been reported, including technical errors, equipment malfunction, filter malposition, an enlarged vena cava, and thrombus fragmentation (4). The migration of a properly deployed IVC filter is an uncommon occurrence, with the reported incidence ranging from 0% to 2% (5). Complete iatrogenic displacement into the cardiac chambers or pulmonary artery is exceedingly rare, occurring in approximately 0.1% to 1.2% of cases (6). In 2025, Bai et al. identified 156 cases of intracardiopulmonary IVC filter migration over a 15-year period. Complete filter migration occurred in 22.8% (34/156), most commonly to the right atrium (RA), followed by the RV, tricuspid valve, and pulmonary artery. Notably, the migration pattern differed substantially for fractured filter struts, with 48.1% to the pulmonary artery and 36.3% to the RV. Furthermore, approximately 50% of unrecovered IVC filters and fractured struts were located to the pulmonary artery (7). Since the structural design of an expanded IVC filter makes it prone to entanglement with the tricuspid valve complex, it is unlikely to embolize into the pulmonary artery. In our case, the migration of the IVC filter was caused by an inverted device orientation and subsequent entanglement of the filter struts during release. This reduced the effective diameter of the filter, allowing it to pass through the tricuspid valve complex and lodge in the LPA.

If the displaced filter is not removed, it may carry significant risks of mechanical complications of the pulmonary arteries and the right heart. Furthermore, a filter position in the pulmonary artery acts as a nidus for pulmonary thromboembolism, particularly in patients with active DVT. In recent years, percutaneous endovascular retrieval has become the preferred solution to IVC filter displacement due to its minimally invasive nature. However, the procedure itself demands high technical precision to avoid iatrogenic injury to the pulmonary vasculature, cardiac valves, or myocardium. Although the procedural costs associated with advanced endovascular techniques are significantly higher compared to those of standard endovascular retrieval, these approaches do not differ significantly in terms of comorbidities or mortality (8).

There are multiple endovascular retrieval techniques available for completing complex IVC filter retrieval, including the standard loop snare technique, guidewire-with-wire-loop snare technique, endobronchial forceps, and laser sheath-assisted extraction (9). The standard coaxial snare technique remains effective for filters with a centrally positioned, nonembedded apex and achieves technical success in the majority of routine retrievals (10). For the filter and remnants severely deviated from the vascular central axis, curved inner sheaths provide directional support to facilitate the snare engagement of displaced filter hooks (11). When filter apices are embedded within fibrin caps or adhered to vascular walls, the modified loop-wire technique, which can grasp the fibrin cap with a reverse-curve catheter, can be used. In cases in which filter encasement or wall incorporation precludes snare engagement altogether, rigid endobronchial or endoscopic forceps can be used to dissect fibrous tissue from the filter hook prior to capture, with a reported technical success rates of 96% being reported in a dedicated series study (12). The excimer laser originally developed for pacemaker lead has been adapted for photothermally ablating the surrounding fibrous tissue, particularly for scenarios where filter struts embed within the caval wall and the filter fails to collapse even after snare engagement.

Advanced retrieval techniques are associated with substantially higher complication rates than are standard approaches, with the literature indicating a 4-fold and 13-fold increases in overall and major complications, respectively (13). Beyond retrieval technique, filter design itself is increasingly recognized as a determinant of retrieval complexity (14). Grange et al. conducted a comparative analysis of 539 patients implanted with either conventional ALN IVC filters (ALN Implants Chirurgicaux, Bormes-Les-Mimosas, France) or novel optional antitilting IVC filters (OATFs) equipped with auxiliary antitilting struts and antipenetration loops (15). OATFs exhibited markedly smaller tilt angles both at implantation and retrieval, consistent with previous research documenting a tilt angle >15° as a predictor of complex retrieval procedures (14). The Denali filter used in our case, similarly to conventional ALN filters, only adopts single-layer conical struts lacking built-in antitilting components. Such a structure often leads to strut overlap and entanglement when deployed at an abnormal angle, which explains the complication that observed in our patient. Accordingly, new-generation IVC filters with native antitilting structures may lower the orientation-related retrieval risks in cases such as ours, although further research is required to verify their efficacy for migrated or embolized filters.

In our case, successful retrieval was facilitated by a systematic approach that combined coaxial sheath stabilization with sequential mechanical resheathing of the filter struts. First, the retention of an extra stiff guidewire in the target branch provided a stable “rail” or fulcrum for the dual-sheath system. This stability was crucial for counteracting the respiratory and cardiac cycle-induced motion of the pulmonary artery, ensuring the snare could accurately engage the retrieval hook. Second, the telescoping dual-sheath configuration (14 F and 10 F) provided superior mechanical support. This coaxial arrangement allowed for the incremental collapse and controlled resheathing of the filter struts, minimizing the risk of vessel wall trauma during withdrawal.

IVC filter implantation is a mature and generally safe procedure. When rare and complex complications such as distal migration occur, they can be successfully managed through meticulous procedural planning and the judicious application of available endovascular tools, selected according to filter position, orientation, and the specific mechanical challenge presented by each case. Before the percutaneous retrieval procedure was performed, written informed consent was obtained from the patient, including consent for the anonymized use of clinical data and imaging for academic publication.

Conclusions

Embolization of an IVC filter into the cardiac valves or pulmonary artery is a rare but high-risk complication. This case illustrates that a specialized snare system, incorporating a telescoping dual-sheath technique under the support of an extra stiff guidewire, can serve as a useful and efficient means to achieving percutaneous recovery of distally migrated devices.

Supplementary

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Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.