Inferior Vena Cava Filter Migration to Right Ventricle With Destruction of Tricuspid Valve: A Case Report

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.

Geometric changes of the inferior vena cava in trauma patients subjected to volume resuscitation

OBJECTIVE

Dynamic changes in anatomic geometry of the inferior vena cava from changes in intravascular volume may cause passive stresses on inferior vena cava filters. In this study, we aim to quantify variability in inferior vena cava dimensions and anatomic orientation to determine how intravascular volume changes may impact complications of inferior vena cava filter placement, such as migration, tilting, perforation, and thrombosis.

METHODS

Retrospective computed tomography measurements of major axis, minor axis, and horizontal diameters of the inferior vena cava at 1 and 5 cm below the lowest renal vein in 58 adult trauma patients in pre-resuscitative (hypovolemic) and post-resuscitative (euvolemic) states were assessed in a blinded fashion by two independent readers. Inferior vena cava perimeter, area, and volume were calculated and correlated with caval orientation.

RESULTS

Mean volumes of the inferior vena cava segment on pre- and post-resuscitation scans were 9.0 cm(3) and 11.0 cm(3), respectively, with mean percentage increase of 48.6% (P < 0.001). At 1 cm and 5 cm below the lowest renal vein, the inferior vena cava expanded anisotropically, with the minor axis expanding by an average of 48.7% (P < 0.001) and 30.0% (P = 0.01), respectively, while the major axis changed by only 4.2% (P = 0.11) and 6.6% (P = 0.017), respectively. Cross-sectional area and perimeter at 1 cm below the lowest renal vein expanded by 61.6% (P < 0.001) and 10.7% (P < 0.01), respectively. At 5 cm below the lowest renal vein, the expansion of cross-sectional area and perimeter were 43.9% (P < 0.01) and 10.7% (P = 0.002), respectively. The major axis of the inferior vena cava was oriented in a left-anterior oblique position in all patients, averaging 20° from the horizontal plane. There was significant underestimation of inferior vena cava maximal diameter by horizontal measurement. In pre-resuscitation scans, at 1 cm and 5 cm below the lowest renal vein, the discrepancy between the horizontal and major axis diameter was 2.1 ± 1.2 mm (P < 0.001) and 1.7 ± 1.0 mm (P < 0.001), respectively, while post-resuscitation studies showed the same underestimation at 1 cm and 5 cm below the lowest renal vein to be 2.2 ± 1.2 mm (P < 0.01) and 1.9 ± 1.0 mm (P < 0.01), respectively.

CONCLUSIONS

There is significant anisotropic variability of infrarenal inferior vena cava geometry with significantly greater expansive and compressive forces in the minor axis. There can be significant volumetric changes in the inferior vena cava with associated perimeter changes but the major axis left-anterior oblique caval configuration is always maintained. These significant dynamic forces may impact inferior vena cava filter stability after implantation. The consistent major axis left-anterior oblique obliquity may lead to underestimation of the inferior vena cava diameter used in standard anteroposterior venography, which may influence initial filter selection.

Incidental Findings in Stress Echocardiography

Sonographic follow-up of surgical or other invasive procedures may lead to incidental findings, and knowledge of a patient’s treatment history is an important factor in properly interpreting these results. The treatment regimen for a patient with deep vein thrombosis and its sequelae can include a combination of anticoagulation, thrombolytic therapy, compression stocking, venous bypass, and stenting of the veins. This case presents an incidental finding during a stress echo examination of embolization into the right ventricle of a previously placed iliofemoral venous stent that required surgical removal. It provides an example of the reasons that sonographers need to understand patient history as well as examination protocols to properly evaluate the sonographic images and to anticipate that there may be unexpected findings with every case.

Inferior Vena Cava Filter Penetration Resulting in Renal Pelvis Rupture With Urinoma Formation

Inferior vena cava (IVC) filter penetration is common and most often asymptomatic. However, penetration may potentially result in a variety of complications, including aortic trauma and small bowel perforation. Described is a case of IVC filter penetration resulting in renal pelvis perforation with urinoma formation.

Predictors of early versus late timing of pulmonary embolus after traumatic injury

OBJECTIVE

To identify risk factors predictive of pulmonary embolus (PE) timing after a traumatic injury.

METHODS

One hundred eight traumatic injury patients with a confirmed diagnosis of PE were classified as early PE (≤4 days, n = 54) or late PE (>4 days, n = 54). Independent predictors of early versus late PE were identified using multivariate logistic regression.

RESULTS

Half the PEs were diagnosed ≤4 days of injury. Only long bone fractures independently predicted early PE (odds ratio 2.8; 95% confidence interval, 1.1-7.1). Severe head injuries were associated with late PE (odds ratio 11.1; 95% confidence interval, 3.9-31). Established risk factors such as age did not affect timing.

CONCLUSIONS

Half the PEs were diagnosed ≤4 days after injury. The risk of early PE appeared highest in patients with long bone fractures, and the benefits of immediate prophylaxis may outweigh risks. Patients with severe head injuries appear to have later PE events. Prospective interventional trials in these injury populations are needed.

Postinjury thromboprophylaxis

PURPOSE OF REVIEW

In trauma patients, pulmonary embolism occurs in up to 4% of cases and carries a mortality of 20-50%. The incidence of deep vein thrombosis (DVT) varies from 5 to 63% depending on patients' risk factors, modality of prophylaxis, and methods of detection. For these reasons, trauma patients require adequate DVT prophylaxis.

RECENT FINDINGS

Spinal fracture or cord injury patients are at particular risk. Increasing injury severity, head injury, older age, lower limb injuries, and obesity are other risk factors. The current standard of care for DVT prophylaxis is enoxaparin (a low molecular weight heparin) as long as anticoagulation is not contraindicated. Unfractionated heparin alone does not provide sufficient protection against DVT. Selective factor Xa inhibitors such as fondaparinux are showing promising results. Other strategies for pulmonary embolism prevention include: graduated compression stockings, sequential compression devices, continuous passive motion, and prophylactic inferior vena cava filter. There is lack of consensus regarding the optimal DVT prophylaxis in trauma patients and few level I recommendations exist.

SUMMARY

Best practice in thromboprophylaxis for trauma patients will remain on the basis of recommendations until definitive risk-benefit ratios are determined to justify the use of various mechanical and pharmacological measures, in combination or alone.