Placing a New Filter before Removing Embolized Nonconical Filter: A Report of 13 Cases

Antegrade and Retrograde Approaches with a Mechanical Thrombectomy Device for the Treatment of Acute Lower Limb Deep Vein Thrombosis

OBJECTIVE

To examine the efficacy of antegrade and retrograde approaches with the AngioJet thrombectomy device for the treatment of acute lower limb deep vein thrombosis (DVT) and to evaluate the necessity of filter placement.

METHODS

The clinical data of patients with acute lower limb DVT treated with the AngioJet device from January 2021 to June 2023 were retrospectively analyzed. The patients were divided into the antegrade and retrograde treatment groups according to the surgical approach and the direction of valve opening. The thrombosis interception rate of the filter, incidence of pulmonary embolism (PE), thrombectomy effectiveness, venous obstruction rate, and thrombosis recurrence rate of each treatment group were evaluated. In addition, factors affecting patency were analyzed.

RESULTS

AngioJet was employed for 84 patients with acute lower limb DVT, treating a total of 88 limbs. The thrombosis interception rate of the filter was 35.7% (30 patients). The incidence of new PE or PE exacerbation was 6.0% (5 patients), and a filter retrieval rate of 97.6% (82 patients) was detected. Thrombus removal of grade III occurred in 35 (64.8%) of the 54 limbs (61.4%) in the antegrade treatment group versus 13 (38.2%) of the 34 limbs (38.6%) in the retrograde treatment group (P < 0.05). At 3 months, venous patency and bleeding events involved 52 (96.3%) and 4 (7.4%) limbs in the antegrade treatment group, respectively, versus 29 (85.3%) and 2 (5.9%) in the retrograde treatment group, respectively (P > 0.05). Regression analysis was performed to determine factors that may affect 3-month patency in both groups. Statistically significant linear relationships were found between 3-month patency and thrombus removal rate [odds ratio [OR] = 0.546 (0.326, 0.916)], thrombus formation time [OR = 1.018 (1.002, 1.036)], and preoperative thrombosis score [OR = 1.012 (1.002, 1.022)] in the antegrade treatment group, as well as thrombus removal rate [0.473 (0.229, 0.977)] in the retrograde treatment group. In regression analysis of factors affecting patency in both groups and the venous clinical severity score/Villalta score, a statistically significant linear relationship was found between thrombus formation time and the venous clinical severity score in the antegrade treatment group [0.576 (0.467, 0.710)].

CONCLUSIONS

Both antegrade and retrograde approaches are safe and effective for the treatment of acute lower limb DVT. There are no differences in 3-month deep vein patency and post-thrombotic syndrome (PTS) incidence rates. Individuals with acute lower limb DVT are at high risk of thrombus shedding after treatment with AngioJet thrombectomy, and placement of a vena cava filter (VCF) is recommended for effective interception.

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.

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.