Laser-Assisted Removal of Embedded Vena Cava Filters: A First-In-Human Escalation Trial in 500 Patients Refractory to High-Force Retrieval

Abstract

Background Many patients are subject to potential risks and filter-related morbidity when standard retrieval methods fail. We evaluated the safety and efficacy of the laser sheath technique for removing embedded inferior vena cava filters. Methods and Results Over an 8.5-year period, 500 patients were prospectively enrolled in an institutional review board-approved study. There were 225 men and 275 women (mean age, 49 years; range, 15-90 years). Indications for retrieval included symptomatic acute inferior vena cava thrombosis, chronic inferior vena cava occlusion, and/or pain from filter penetration. Retrieval was also offered to prevent risks from prolonged implantation and potentially to eliminate need for lifelong anticoagulation. After retrieval failed using 3X standard retrieval force (6-7 lb via digital gauge), treatment escalation was attempted using laser sheath powered by 308-nm XeCl excimer laser system (CVX-300; Spectranetics). We hypothesized that the laser-assisted technique would allow retrieval of >95% of embedded filters with <5% risk of major complications and with lower force. Primary outcome was successful retrieval. Primary safety outcome was any major procedure-related complication. Laser-assisted retrieval was successful in 99.4% of cases (497/500) (95% CI, 98.3%-99.9%) and significantly >95% (P<0.0001). The mean filter dwell time was 1528 days (range, 37-10 047; >27.5 years]), among retrievable-type (n=414) and permanent-type (n=86) filters. The average force during failed attempts without laser was 6.4 versus 3.6 lb during laser-assisted retrievals (P<0.0001). The major complication rate was 2.0% (10/500) (95% CI, 1.0%-3.6%), significantly <5% (P<0.0005), 0.6% (3/500) (95% CI, 0%-1.3%) from laser, and all were successfully treated. Successful retrieval allowed cessation of anticoagulation in 98.7% (77/78) (95% CI, 93.1%-100.0%) and alleviated filter-related morbidity in 98.5% (138/140) (95% CI, 96.5%-100.0%). Conclusions The excimer laser sheath technique is safe and effective for removing embedded inferior vena cava filters refractory to high-force retrieval. This technique may allow cessation of filter-related anticoagulation and can be used to prevent and alleviate filter-related morbidity. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01158482.

Keywords: IVC filter; endovascular; filter retrieval; laser.

Conflict of interest statement

None.

Figures

Figure 1. A 48‐year‐old woman underwent prophylactic placement of an inferior vena cava (IVC) filter 9 years prior at an outside hospital after sustaining polytrauma and multiple long bone fractures.

The patient recovered from her injuries and underwent attempted filter removal at her local hospital ≈1 year later, but this was unsuccessful. Several years later, during a routine evaluation by her primary physician, her indwelling filter was rediscovered. Her local physician recommended reevaluation for potential filter removal to avoid risks associated with long‐term implantation, and she was referred to our center to undergo advanced filter retrieval. A, Spot fluoroscopic image shows a Günther‐Tulip IVC filter. The filter hook is deformed and straightened (arrow) from prior manipulation indicating that high force (>6–7 lb) was previously applied to the filter (exceeding the metallic yield strength) during the failed retrieval attempt. B, Initial IVC venogram shows a patent vein with evidence of filter leg penetration. C, Fluoroscopic images demonstrate attempted capture of the Günther‐Tulip IVC filter using a standard snare and sheathing method, but the distal filter legs cannot be sheathed despite confirming 6 lb of tension applied along the attachment sites (arrows). D, After laser activation and ablation through the adherent scar tissue, the filter is completely captured within the laser sheath (arrows) using only 3 lb of tension. E, Post‐retrieval venogram shows expected postprocedure vasospasm, but there is no acute injury and no extravasation.

Figure 2. Illustration of laser‐assisted filter retrieval.

A, A chronically embedded inferior vena cava (IVC) filter is shown with fibrotic tissue along the endoluminal contact points. Distal leg penetration is also present. The filter is confirmed to be embedded after standard sheathing methods and high force (up to 6–7 lb) fail to remove the filter. B and C, The laser‐tipped sheath is advanced over the filter until reaching the point of resistance. While activating the excimer laser to ablate through the fibrotic tissue, only one half (3–3.5 lb) of the prior high‐force tension is needed to capture the filter legs. At a 308‐nm wavelength, the excimer laser ablates 50 to 100 μm from the laser tip sheath. Since the energy is emitted parallel to the vessel walls, the risk of significant vessel injury is minimized. Once the adherent tissue is ablated, the distal filter legs including the penetrating components can now be retracted safely into the vessel lumen and captured within the laser sheath. D, Using a lower amount of force, the chronically embedded filter is now completely and safely detached from the IVC without vessel wall injury.