Midterm Recanalization after Arterial Embolization Using Hydrogel-Coated Coils versus Fibered Coils in an Animal Model

In Vitro Head-to-Head Comparison of Flow Reduction between Fibered and Non-Fibered Pushable Coils

PURPOSE

To compare the embolization effects of a non-fibered pushable coil with a conventional fibered pushable coil in an in vitro bench-top experiment.

MATERIALS AND METHODS

A simplified vascular phantom with 4 channels (1 for the non-fibered coil, 1 for the fibered coil, and 2 for continuous circuit flow) was used. A single coil of the longest length was inserted to evaluate the effect of single-coil embolization, and 3 consecutive coils were inserted to assess the effect of multiple-coil embolization. Post-embolization angiography was performed to obtain flow variables (time to peak [TTP], relative peak intensity [rPI], and angiographic flow reduction score [AFRS]) from time density curves. The packing densities of the two coil types were calculated, and the AFRS of each channel was determined by dividing the TTP by the rPI.

RESULTS

When inserting a single coil, the conventional fibered coil demonstrated better flow reduction, as indicated by a higher AFRS (25.6 vs. 17.4, P=0.034). However, the non-fibered coil exhibited a significantly higher packing density (12.9 vs. 2.4, P=0.001). Similar trends were observed with multiple coils.

CONCLUSION

The conventional fibered pushable coil showed better flow reduction efficiency, while the non-fibered pushable coil had a higher packing density, likely due to the flexibility of the coil loops. A better understanding of the distinct characteristics of different pushable coils can enhance the outcomes of various vascular embolization.

Transarterial Embolization of Simple Pulmonary Arteriovenous Malformations: Long-Term Outcomes of 0.018-Inch Coils versus Vascular Plugs

PURPOSE

To compare the safety, effectiveness, and persistence rates of 0.018-inch coils with those of Amplatzer vascular plugs (AVPs; Abbott Vascular, Abbott Park, Illinois) for the treatment of pulmonary arteriovenous malformations (PAVMs) in response to a growing concern that 0.018-inch coil embolization would increase the long-term persistence rate.

MATERIALS AND METHODS

This is a retrospective, single-center study of a database (2002-2020) of 633 PAVM embolizations. Complex PAVMs and those not embolized with 0.018-inch coils or plugs were excluded. PAVM embolization material was classified into 4 groups: (a) 0.018-inch nonfibered coils (NFCs), (b) 0.018-inch fibered coils (FCs), (c) NFCs and FCs, or (d) plugs. Persistence was defined as flow through the PAVM on digital subtraction angiography (DSA) or as <30% diameter reduction of the aneurysmal sac on unenhanced computed tomography (CT). Kaplan-Meier analysis and Cox regression were used to assess PAVM's persistence-free survival.

RESULTS

A total of 312 PAVM embolizations with NFCs (43 PAVMs), FCs (127 PAVMs), NFCs and FCs (12 PAVMs), or plugs (130 PAVMs) in 109 patients (28% men; mean age = 49 years) were included. All PAVM embolizations were technically successful without any major adverse events. PAVM persistence-free survival rates at 10 years' follow-up were 40.8% versus 44.7% in the NFC and FC groups (P = .22) and 47.3% versus 81.0% in the 0.018-inch coil (NFC or FC) and plug groups (P < .0001), respectively. There were 0.43 (79/182) and 0.08 (10/130) re-embolization procedures per PAVM in the 0.018-inch coil and plug groups, respectively (P < .001).

CONCLUSIONS

PAVM embolization with 0.018-inch coils was safe, but persistence rate with PAVM embolization was significantly higher than that with plugs, with no significant differences between FCs and NFCs.

Current trends in image-guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

Benefit of vessel closure with the Azur CX Peripheral Coil System in small children with complex CHD

Vessel occlusion is a frequently used procedure to close congenital or acquired collaterals or communications. We report two cases of successful vessel closure, in small infants with CHD, using the Azur CX Peripheral Coil System. The low profile of the device, the controlled delivery of the coils, and the delivery through a microcatheter make it particularly interesting for the occlusion of highly tortuous vessels in children.

Retrospective Comparison of Pulmonary Arteriovenous Malformation Embolization with the Polytetrafluoroethylene-Covered Nitinol Microvascular Plug, AMPLATZER Plug, and Coils in Patients with Hereditary Hemorrhagic Telangiectasia

PURPOSE

To evaluate effectiveness of the polytetrafluoroethylene-covered nitinol mesh microvascular plug (MVP) and compare it with other devices in pulmonary arteriovenous malformation (PAVM) embolization in patients with hereditary hemorrhagic telangiectasia (HHT).

MATERIALS AND METHODS

Twenty-five patients (average age 35 y; range, 15-56 y) with hereditary hemorrhagic telangiectasia (HHT) and de novo PAVM embolization with at least 1 MVP between November 2015 and May 2017 were retrospectively evaluated. Retrospective data were also obtained from prior embolization procedures in the same patient population with other embolic devices dating back to 2008. Technical success, complications, PAVM persistence rates, and category of persistence were analyzed.

RESULTS

In 25 patients, 157 PAVMs were treated: 92 with MVP, 35 with AMPLATZER vascular plug (AVP), 6 with AVP plus coils, and 24 with coils. The per-PAVM technical success rates were 100% with MVP; 97%, AVP; 100%, AVP plus coils; and 100%, coils. PAVM persistence rates and median follow-up were as follows: MVP, 2% (1/92) (510 d); AVP, 15% (3/20) (1,447 d); AVP plus coils, 20% (1/5) (1,141 d); coils, 46.7% (7/15) (1,141 d). Persistence owing to recanalization for MVP, AVP, AVP plus coils, and coils was 2%, 15%, 0%, and 33%. No difference was found between persistence rates of MVP vs AVP (P = .098). Embolization with a vascular plug (MVP or AVP) with or without coils had a statistically significant lower persistence rate (5.4%) than embolization with coils alone (46.7%) (P = .022).

CONCLUSIONS

PAVM embolization with MVP had a high technical success rate and a low persistence rate comparable to AVP and lower than coil embolization alone.