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

ELECT: prospective, randomized trial comparing microvascular plug versus platinum-fibered microcoils for embolization of aneurysm sac side branches before endovascular aortic aneurysm repair

BACKGROUND

Preemptive selective embolization of aneurysm sac side branches (ASSBs) has been proposed to prevent type II endoleak after endovascular aortic aneurysm repair (EVAR). This study aimed to explore if an embolization strategy using microvascular plugs (MVP) reduces intervention time and radiation dose compared to platinum-fibered microcoils. Furthermore, the effectiveness of the devices in occluding the treated artery was assessed.

METHODS

Sixty patients scheduled for EVAR underwent percutaneous preemptive embolization of ASSBs using MVPs or coils after a 1:1 randomization. Follow-up imaging was performed during aortic stentgraft implantation.

RESULTS

Overall, 170 ASSBs were successfully occluded (83 arteries by MVPs and 87 by coils) and no acute treatment failure occurred. The mean procedure time was significantly lower in the group treated with MVPs (55 ± 4 min) compared to coil occlusion (67 ± 3 min; p = 0.018), which was paralleled by a numerically lower radiation dose (119 Gy/cm2 vs. 140 Gy/cm2; p = 0.45). No difference was found for contrast agent use (34 ml MVP group vs 35 ml coil group; p = 0.87). At follow-up, reopening of lumbar arteries was seen in nine cases (four after coil embolization; five after MVPs).

CONCLUSION

Both microvascular plugs and coils can be effectively used for preemptive embolization of aneurysm sac side branches before EVAR. Use of plugs offers a benefit in terms of intervention time.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03842930 Registered 15 February 2019.

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.

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.

Percutaneous Embolization of Biliary Leaks: Initial Experience with Extravascular Application of a PTFE-Covered Microplug

PURPOSE

This paper describes the initial experience with a PTFE-covered microplug to perform extravascular embolizations in patients with iatrogenic biliary leaks.

MATERIALS AND METHODS

A retrospective multicenter analysis has been conducted on seven patients. All were symptomatic for abdominal pain and had an abdominal drainage adjacent to the supposed site of leakage. The biliary output of the drainage was monitored daily. Biliary leak etiology was iatrogenic: four after laparoscopic cholecistectomy for gallstones, one after explorative laparotomy for pancreas head adenocarcinoma with concomitant cholecistectomy for gallstones, and two after long-standing internal-external right biliary drainage for cholangiocarcinoma. In four cases leakage sourced from cystic duct stump, in one from an aberrant bile duct and in two from bilio-cutaneous fistula. Technical success was considered leak resolution at the last cholangiography. Clinical success was defined improvement in the clinical conditions together with progressive resolution of the biliary output from the abdominal drainage until removal.

RESULTS

Technical and clinical successes were 100%. A 5 mm microplug was adopted in five cases of post-cholecistectomy leaks. A 3 mm microplug and a 9 mm microplug were deployed in the two cases of peripheral leaks related to bilio-cutaneous fistulas. In three patients additional embolics (coils in two cases; spongel slurry in one case) were required. Minor complications occurred in three patients.

CONCLUSION

This initial experience on seven patients with iatrogenic biliary leaks demonstrated that percutaneous transhepatic PTFE-covered microplug embolization is technically feasible and clinically effective to achieve leak resolution. Future researches with larger samples are needed to confirm these findings.

Successful embolization of a congenital intra-hepatic arterioportal fistula in a neonate with the MVP Microvascular Plug system (MVP-3Q)

This case report describes a neonate with an antenatally diagnosed vascular anomaly of the liver. Ultrasound at birth confirmed an arterioportal fistula communicating the left hepatic artery and an anterior branch of the right portal vein. Computer tomography angiography on day 7 of life redemonstrated the arterioportal fistula and defined the vascular anatomy for potential treatment. Transarterial embolization of the arterioportal fistula was performed at 3 weeks of life using an MVP Microvascular Plug System 3Q (Reverse Medical Corp, Irvine, CA, USA). Intra-procedural angiography showed successful occlusion of the fistula, patency of the portal vein with hepatopetal flow, and patency of the hepatic artery with no signs of arterial or venous thrombosis. There were no intra- or post-procedure complications. Multiple follow-up ultrasounds at 1-13 months showed stable occlusion of the embolized fistula with no evidence of recanalization, with the patient having a normal life and no sequelae. This case illustrates a successful novel approach to manage the rare condition of a solitary hepatic arterioportal fistula in a neonate using the MVP system. Current literature on congenital arterioportal fistulas and the MVP system is reviewed.

Use of the Medtronic Microvascular Plug 7Q for transcatheter closure of large patent ductus arteriosus in infants weighing less than 2.5 kg

Background

The sole Food and Drug Administration‐approved device for transcatheter closure of the patent arterial duct in premature infants is indicated for patent ductus arteriosus (PDAs) ≤ 4 mm in diameter. We report a two‐center experience with transcatheter closure of large PDAs (>4 mm) in infants weighing <2.5 kg using the Microvascular Plug 7Q (MVP‐7Q) device.

Methods

This is a retrospective review of departmental databases and medical charts to define patient cohort and report demographic, procedural, and follow‐up data.

Results

Twenty‐two patients (12 male) with a median gestational age and birthweight of 25.5 weeks (interquartile range [IQR] = 24–28) and 800 g (572–1075), respectively, underwent attempted PDA occlusion with the MVP‐7Q using a transvenous approach. The median age and weight at the time of PDA occlusion was 32 days (IQR = 24–28) and 1100 g (IQR = 960–1700), respectively. The median PDA length was 12 mm (IQR = 11–12.65). The median PDA diameters at the aortic and pulmonary ends were 5.1 (IQR = 4.9–5.5) and 4.8 mm (IQR = 4.6–5.3), respectively. Successful device occlusion was achieved in 20 patients (91%). There were two failed attempts: One due to inappropriate sizing, and the other secondary to left pulmonary artery stenosis. There were no procedural complications and no residual shunting on follow‐up.

Conclusions

The MVP‐7Q is safe and effective for transcatheter closure of large (>4 mm) PDAs in infants <2.5 kg. The lack of retention disks may help with avoiding impingement on surrounding vessels.

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.