The protocol defined technical placement success as: deployment of filter in a location suitable to provide sufficient mechanical protection against PE with no filter deformation, fracture, premature release, or clinical migration (caudal or cranial movement of a filter resulting in a surgical or endovascular intervention).

The hypothesis was tested only for patients receiving Celect filters, in accordance with the study protocol.

MAEs were defined as clinical perforation, clinical migration, clinical fracture, embolization of the filter or filter fragments to the heart or lungs, IVC thrombotic occlusion, new symptomatic DVT while the filter is indwelling, access site complications with clinical sequelae, and procedure-/device-related death.

Clinical perforation - Protrusion of filter legs through the wall of the IVC causing hemorrhage or hematoma or touching, impressing, or perforating another organ. Documented using CT.

Clinical migration - Caudal or cranial movement of a filter resulting in surgical or endovascular intervention.

Clinical fracture - A loss of structural integrity (breakage or separation) of the filter identified by imaging and associated with clinical sequelae and/or requiring intervention.

The CIP defined methodology for analysis of the primary endpoint relied on Kaplan-Meier estimation. However, a large number of patients were censored (n=235), primarily due to filter retrieval (n=204).

The hypothesis was tested only for patients receiving Celect filters, in accordance with the study protocol.

MAEs were defined as clinical perforation, clinical migration, clinical fracture, embolization of the filter or filter fragments to the heart or lungs, IVC thrombotic occlusion, new symptomatic DVT while the filter is indwelling, access site complications with clinical sequelae, and procedure-/device-related death.

A filter retrieval is considered a successful safety result through 12 months, regardless of when the retrieval occurred.

The hypothesis was only tested for patients receiving Celect filters, in accordance with the protocol.

Rate of technical placement success and 12-month freedom from new symptomatic PE while a filter is indwelling for the combined patient population (i.e., the Celect and Günther Tulip strata).

The protocol defined technical placement success as: deployment of filter in a location suitable to provide sufficient mechanical protection against PE with no filter deformation, fracture, premature release, or clinical migration (caudal or cranial movement of a filter resulting in a surgical or endovascular intervention).

MAEs were defined as clinical perforation, clinical migration, clinical fracture, embolization of the filter or filter fragments to the heart or lungs, IVC thrombotic occlusion, new symptomatic DVT while the filter is indwelling, access site complications with clinical sequelae, and procedure-/device-related death.

Clinical perforation - Protrusion of filter legs through the wall of the IVC causing hemorrhage or hematoma or touching, impressing, or perforating another organ. Documented using CT.

Clinical migration - Caudal or cranial movement of a filter resulting in surgical or endovascular intervention.

Clinical fracture - A loss of structural integrity (breakage or separation) of the filter identified by imaging and associated with clinical sequelae and/or requiring intervention.

Filter interaction with IVC is defined as :

Grade 2: Filter strut is entirely outside of the IVC lumen and within the retroperitoneum as evidenced by a "halo" of retroperitoneal fat around axially viewed strut.

Grade 3: Filter strut is touching, impressing, or perforating another organ (e.g., liver, bowel, aorta, psoas muscle, vertebral body, lymph nodes).

Filter migration : Change in filter position compared to its deployed position (cranial or caudal).

Filter fracture : Any loss of structural integrity (breakage or separation) of the filter identified by imaging or autopsy. Documented by imaging or at autopsy.

Filter embolization : Post-placement movement of the filter or its components to a distant anatomic site completely out of the target zone (i.e., heart/lungs). Documented by imaging or autopsy.

The filters may be retrieved if clinically indicated. The IVC filter and IVC were assessed on imaging before a retrieval attempt.

(The filter retrieval rate= the total number of filter retrieved / the total number of filter retrieval attempted)

Patients with filter retrieval attempted