Prospective Study of Polytetrafluoroethylene-Covered Microplugs and Detachable Coils for Embolization of Pulmonary Arteriovenous Malformations: Technical Results, Procedure Times, and Costs

PURPOSE

To determine time to occlusion and procedure costs of embolization of pulmonary arteriovenous malformations (PAVMs) using a polytetrafluoroethylene-covered microplug compared with embolization using detachable coils.

MATERIALS AND METHODS

In this prospective study, 37 patients (mean age, 39.1 years [SD ± 17.6]) with 82 PAVMs underwent embolization with microplug or detachable coils between April 2019 and January 2023. Technical success, procedure time intervals, and costs were analyzed.

RESULTS

In 37 patients, 82 PAVMs and 101 feeding arteries were successfully treated (microplug, 64; microplug + another device, 5; detachable coils alone, 32). Time from embolic device inserted into the catheter to device deployed and time to occlusion differed significantly between microplug and detachable coil cohorts (P < .0001 for both). Embolization with ≥1 microplug had a significantly shorter occlusion time than embolization with detachable coils (median, 10.0 minutes saved per feeding artery) (P < .0001). Compared with detachable coil embolization, microplug embolization saved a median of 9.0 minutes per feeding artery (P < .0001) and reduced room cost by a median of $429 per feeding artery (P < .0001). Device costs per feeding artery did not differ significantly between microplug ($2,790) and detachable coil embolization ($3,147) (P = .87).

CONCLUSIONS

Compared with coils, microplugs had an equally high technical success rate but significant time to occlusion and room costs savings per feeding artery. Total room cost and device cost together did not differ significantly between microplugs and coils. Microplugs may be considered technically effective and at least cost-neutral for PAVM embolization where clinically appropriate.

Novel Technique for Intentional Occlusion of Directional Branches During Complex Endovascular Aortic Repair Using Microvascular Plugs

PURPOSE

To demonstrate the feasibility and outcomes of using the microvascular plug (MVP) for intentional occlusion of directional branches (DB) during complex endovascular aortic procedures.

CASE REPORT

Two patients were treated with the off-the-shelf four-branched Zenith t-Branch thoracoabdominal stent-graft (Cook Medical, Bloomington, Ind). In both cases, the renal arteries (on one side in patient #1 and on both sides in patient #2, respectively) were occluded at time of index intervention. Preoperative planning included the intentional occlusion of each DB with one 7Q-MVP. Technical success was achieved in all cases and maintained at mid-term follow-up (12 months and 36 months, respectively).

CONCLUSIONS

Use of the MVP appears to be feasible and effective for intentional occlusion of DB during complex endovascular aortic repair. This novel and simple technique may present some unique technical advantages, allowing precise placement of the device while avoiding extension using a bridging stent and DB cannulation with larger sheaths.

Embolisation Using Microvascular Plugs for Peripheral Applications: Technical Results and Mid-Term Outcomes

The Micro Vascular Plug® (MVP, Medtronic) is a mechanical embolic agent available in small sizes that allows for distal embolisation. The objective of this retrospective observational single-centre study was to assess MVP embolisation procedures performed at a university hospital. The 33 patients who underwent MVP embolisation in 2021 were included (mean age, 64; 24 males and 9 females). The primary endpoint was technical success, which was defined as a full first-attempt occlusion with one or more MVPs, as documented on the end-of-procedure angiogram. In all patients, 51 MVPs were used overall, with other embolic agents in 23 of the 33 cases (usually coils and/or glue); 22 of the 33 procedures were emergent for bleeding and 11 were planned for other indications. Of the three technical failures, two were due to an angled target artery configuration precluding microcatheterisation and one to failure of the device to release from its wire. The technical success rate was thus 90.9%. No patient experienced MVP migration or other major complications. Five patients had recurrent clinical symptoms; in four cases, the cause was collateral development, and in one case, the cause was incomplete initial embolisation. No instances of recanalisation were documented during the short follow-up of 12 months, for a 100% secondary clinical success rate. At our tertiary-level centre, the MVP was both effective and safe for peripheral applications. Interventional radiologists should be conversant with the techniques and indications of MVP embolisation.

Embolization of vascular abnormalities in children with congenital heart diseases using medtronic micro vascular plugs

This study aimed at evaluating our experience with Micro Vascular Plug (MVP) for embolization of vascular abnormalities in children with congenital heart diseases (CHDs). MVP is one of the most recent additions to the armamentarium for peripheral embolization. Data on its use in congenital cardiology are scarce. Medical records of children with CHDs who had embolizations with MVPs between April 2015 and September 2020 were reviewed. Immediate and follow-up data were assessed. A total of 153 patients underwent 172 procedures during which 240 embolizations using 259 MVPs were attempted. Median age and weight were 34.9 months (IQR, 4-75 months) and 12.5 kg (IQR, 4.8-19.4 kg), respectively. Targets were abnormal systemic arteries (n = 163), patent arterial ducts (n = 26), venous (n = 45), and coronary-cameral fistulas (n = 6). Median vessel diameter was 3.3 mm (IQR, 2.5-4 mm). Veins were larger than arteries (2.3 mm > 2.1 mm, p < 0.01). MVPs were implanted in narrower diameters compared to manufacturer's recommendations. Compared to veins, solitary implanted MVPs in arteries were additionally oversized at 12.4%, 5.1%, and 7.9% for MVP-3Q, 5Q, and 7Q, respectively. Additional occlusion material (16.7%) and 2 MVPs (5.8%) were needed at the same site for complete closure. Implantation and procedure success rates were 99.2% and 96.7%, respectively. Five complications were treated percutaneously (n = 4) and surgically (n = 1). Efficacy of vascular embolization using MVPs was demonstrated in the largest cohort of children with CHDs and a variety of clinical settings. Immediate and stable closure is obtained with a single device in most cases. Detailed device selection chart according to vessel type and diameter is proposed to achieve intended outcomes.

Embolic Materials: Understanding the Ocean of Choices

Embolization is a fundamental procedure that interventional radiologists perform on a daily basis to treat a variety of diseases. The disease processes for which embolization is considered a safe and effective treatment are continuously expanding, as are the embolization materials available for use. To achieve optimal clinical outcomes and minimize complications, it is imperative that the interventional radiologist understands the properties, strengths, and weaknesses of each class of embolic and specific embolic products. This is a continuous process as new materials are always becoming available. This article reviews the different classes of embolic materials, discusses strengths and weaknesses, and reviews areas of innovation.

The Common but Complicated Tool: Review of Embolic Materials for the Interventional Radiologist

Embolization is an important and widely utilized technique in interventional radiology. There are a variety of different categories and individual products which can be utilized to perform embolization. Understanding the different classes of embolic agents, the important features of each of these classes including strengths and limitations, and the variation in individual products within the classes is critical for interventional radiologist to practice safely and effectively. This article reviews the different kinds of embolics and relays some of the pertinent physical and chemical properties of individual products which should be considered when determining which embolic to select for a given purpose.

Evolving Diagnostic and Therapeutic Options for Visceral Artery Aneurysms

BACKGROUND

Visceral artery aneurysms (VAAs) are associated with a very high mortality rate when ruptured and may present as a surgical emergency. Due to their rarity and varying pathophysiology, literature concerning the optimal management of VAAs is limited. This review evaluates the evolving management options for VAAs with a focus on open and endovascular repair.

METHODS

A combination of databases including OVID, PubMed and Medline were used to perform a literature search. Search terms employed include 'visceral artery aneurysms', 'angiography', '3D-volumetric rendering', 'management', 'open repair' and 'endovascular repair', amongst others.

RESULTS

3D modelling in conjunction with existing diagnostic techniques, such as computed tomography and angiography, may improve diagnostic sensitivity. The literature surrounding operative management of VAAs highlights the effectiveness of endovascular repair for anatomically suitable aneurysms. Advances in endovascular technologies may expand the type and number of aneurysms amenable to catheter-based treatment approaches. For aneurysms not amenable to endovascular treatment, or those with an emergency indication, open repair remains an appropriate management choice.

CONCLUSION

Although rare, VAAs pose a high mortality risk, especially when ruptured. Practical limitations that restrict current operative approaches may be overcome by recent developments including novel neurointerventional techniques that have been applied in VAA management.

Embolization with MVP (Micro Vascular Plug®): experience on 104 patients in emergent and elective scenarios

AIM

To describe a 3 years experience of peripheral arterial embolization with Micro Vascular Plug (MVP) (Medtronic, USA).

MATERIALS AND METHODS

The following parameters were investigated: type of vascular injury, anticoagulation therapy at time of procedure, anatomical district, caliper of the target artery, course of the landing zone, additional embolics, technical and clinical success, device related clinical complications. Technical success was defined as complete embolization without deployment of additional embolics after MVP release. Primary clinical success was considered as hemodynamic stability in emergency setting and resolution of the underlying vascular pathology in elective cases; secondary clinical success was considered clinical success after a second embolization session.

RESULTS

116 MVP have been released in 104 patients (67 males and 37 females; mean age 61.3 years). The pullback release technique was adopted in each case. 85 patients were treated in emergent settings while in 19 patients the procedure was scheduled. The overall technical success was 75%. Primary clinical success was 96.1%, secondary clinical success 3% and clinical failure 0.9%. No statistical differences in terms of effectiveness were observed among patients assuming anticoagulation (p-value = 0.6). A straight and longer landing zone were statistically associated with higher technical success compared to curved and shorter ones, (p-values < 0.001 and = 0.048 respectively). MVP-3 and MVP-5 were the most frequently adopted models in this sample, in 29.8% and 49% of the patients respectively. No clinically adverse events directly related to MVP occurred; in 3 cases device migration was registered without clinical complications.

CONCLUSION

MVP is a safe and effective embolic agent. While eventual concomitant anticoagulation therapy did not influence the technical outcome, straight course and length of the landing zone are essential parameters to evaluate before deployment.

Chronic fusiform extracranial vertebral artery aneurysm with recurrent posterior circulation emboli: Case report and review of the literature

We report a case of a 64-year-old man with a fusiform right extracranial vertebral artery aneurysm, spanning over half the extra-cranial V2 (foraminal) segment, presenting with recurrent multi-focal posterior circulation embolic ischaemic stroke. The patient was treated with endovascular embolisation of the right vertebral artery to prevent further thrombo-embolic events. Distal and proximal occlusion of the aneurysmal vertebral artery was performed with a micro-vascular plug with partial aneurysm sack embolisation to aid thrombosis and reduce the risk of recanalisation. Two months post procedure MR angiography confirmed successful aneurysm occlusion with no post-procedural complication. The patient returned to his normal independent life. Endovascular treatment with vessel sacrifice is an effective treatment with low morbidity and we believe the MVP device to be a efficacious option in the vertebral artery.

Amplatzer vascular plug in renal artery embolization: case report and review of the literature

Background

Arterial embolization constitutes a safe and effective therapeutic possibility in the treatment of numerous renal pathologies in election and in urgency. Over the years, numerous embolizing materials have been proposed: fibrin (temporary occlusion), glues, coils, and microspheres. The use of St. Jude Amplatzer vascular plug (AVP) constitutes a more recent and less widespread therapeutic choice, and its use in the renal district is not yet widespread although potentially very valid.

Case presentation

We present 3 renal arterial embolizations performed with AVP performed between January 2019 and February 2020: two patients had a very bulky renal heteroplastic lesion and were candidates for nephrectomy, and a third patient instead was affected by a high-flow FAV post-biopsy. In our experience, the use of AVP for the treatment of renal arteriovenous fistula and neoplastic masses has given excellent results without any complications during and after the treatment. In all cases, a single plug was used which perfectly adapted to the target artery resulting in complete occlusion of the vessel in a short time.

Conclusion

Renal artery embolization performed with AVP has growing potential and numerous advantages in terms of the time of the procedure, speed of embolization, and precision of occlusion, but with a relative increase in costs.

Basic embolization techniques: tips and tricks

Good knowledge of the various approaches of embolization of peripheral bleedings and different embolic materials available is of paramount importance for successful and safe embolization. We review and illustrate the main endovascular and percutaneous techniques used for embolization, along with the characteristics of the different embolic materials, and the potential complications.