Microvascular Plug Research Articles

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

PurposeTo 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 MethodsTwenty-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. ResultsIn 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). ConclusionsPAVM embolization with MVP had a high technical success rate and a low persistence rate comparable to AVP and lower than coil embolization alone.

03:18 PM Abstract No. 114 A single-center experience with proximal radioembolization enabled by distal angiosomal truncation (PREDATr)

A selective approach in transarterial radioembolization (TARE) allows for increased dose conformality which improves both safety and efficacy. Selective TARE is not always feasible in tumors with unfavorable blood supply. Angiosomal truncation of flow using temporary occlusive agents to reduce non-target liver exposure may improve dose conformality when selective administration is not feasible. An IRB-approved review of patients undergoing PREDATr was performed to include vascular evaluation with 99Tc-MAA SPECT-CT prior to TARE and Y-90 Bremsstrahlung SPECT-CT after TARE. The following devices were utilized for flow augmentation: microvascular plug (Medtronic™), retrievable coil (Concerto™, Covidien), gelatin slurry (Surgifoam™, Ethicon), or balloon microcatheter (Sniper™, Embolx). Twenty-two cases comprising primary and secondary hepatic malignancies were treated via PREDATr. The 99Tcm-MAA and a Y-90 Bremsstrahlung SPECT/CT images were evaluated using MIMVista (MIM Software Inc., Cleveland, OH ™) and showed a 21% to 62% peripheral dose reduction and a target dose escalation from 12% to 18% (N=5). Further analysis is being performed using a new version of the software (Sureplan) to assess accuracy. mRECIST assessment was performed in 12/17 cases and found 4 complete responses, 5 partial responses (32-72%), 2 stable diseases and 1 disease progression (new tumor in vein). The temporarily occluded artery was found to be patent on subsequent angiography and/or cross sectional imaging. Mean pre and 3-month post-TARE ALBI scores were 1.4 and 1.6 with ranges of 1-3 and 1-3, respectively. Median pre and 3-month post ECOG scores were 0 and 0 with ranges of 0-2 and 0-1, respectively. Additionally, 5 patients underwent liver transplantation where explant analysis of the treated tumor revealed complete necrosis in 2 patients and >60% necrosis in 3 patients. PREDATr allows for increased conformal dosing in tumors where selective TARE is not feasible.

A Pseudo to Pseudo Connection: Pseudoaneurysm Draining Into the Pseudocyst

Pseudohemobilia or Hemosuccus Pancreaticus (HP) is a rare cause of gastrointestinal (GI) bleeding from an aneurysm of peripancreatic vessels that ruptures into a pancreatic pseudocyst, and blood travels through the pancreatic duct as a conduit entering the GI tract through the ampulla of Vater. We are highlighting a case of a 65-year-old female with past medical history of chronic pancreatitis who presented with multiple episodes of dark tarry stools for one day. Her vitals were stable and systemic examination was unremarkable. Laboratory evaluation was only significant for a hemoglobin of 6.7mg/dl and Doppler ultrasound of the abdomen revealed a 8.3 cm ovoid echogenic structure in the midline near the superior mesenteric artery with bidirectional flow suggesting a pseudoaneurysm raising suspicion for communication with pseudocysts. Contrast-enhanced CT showed multiple pancreatic pseudocysts connecting with a large 7.9 x 7.5 cm pseudoaneurysm close to the pancreatic head. (Figure 1) Emergent angiography was done revealing a large pseudoaneurysm arising from the middle part of the gastroduodenal artery with contrast extravasation into pseudocyst depicting active hemorrhage. (Figure 2) The pseudoaneurysm was embolized by microvascular plug (MVP) devices. Post-embolization angiogram showed preservation of hepatic arterial supply and patent portal vein with good flow towards the liver. (Figure 3) Sandblom first coined the name “hemosuccus pancreatitis” in 1970. (1) It's a rare and potentially lethal cause of GI bleed found mostly in men. (2) Most common cause of HP is the chronic recurrent pancreatitis resulting in pancreatic pseudocysts formation. (3) Pseudocyst induced pressure necrosis and autodigestion by pancreatic enzymes from repeated episodes of pancreatitis weaken the surrounding vessel walls and result in the formation of the pseudoaneurysms. (3) Rupture of these pseudoaneurysms into pseudocysts or sometimes directly into the pancreatic duct heralds GI bleed. This poses a diagnostic and management challenge due to the novelty of the condition and difficulty of diagnosing it with endoscopy because of the intermittent nature of the bleeding. Angiography is considered to be the gold standard as it not only serves a diagnostic role but also as a therapeutic modality. (4) Physicians should keep a high index of suspicion for HP in high-risk patients with a normal endoscopy.1359.tif Figure 1: Contrast-enhanced CT scan of the abdomen reveals a 7.9 x 7.5 cm mass adjacent to the pancreatic head. High-density area(arrow) corresponds to active hemorrhage in the pseudoaneurysm.

Preliminary experience with the micro vascular plug for the treatment of pulmonary arteriovenous malformation: case series of four patients

BackgroundTo describe the preliminary experience using Micro Vascular Plug (MVP) for treatment of pulmonary arteriovenous malformations (PAVMs) with small feeding arteries (3 -5 mm) in four patients with Hereditary Haemorrhagic Telangiectasia (HHT).Material and methodsOne female and three male patients with PAVMs have been treated during 2017. The mean age was 32.5 years; (range: 20–53). All patients underwent contrast echocardiography and computed tomography of the chest to establish the diagnosis.ResultsFour patients with PAVMs were treated with embolisation using the MVP-3Q and MVP-5Q micro plugs. All MVP were placed without complications and with following immediate occlusion of the PAVMs in all three cases. In one case MVP was placed semi selectively. All cases were with the good clinical outcomes.ConclusionMVP is a new detachable embolisation material which is easy to use. Maximal control during the deployment and immediate occlusion of the target vessels can be achieved.

Pulmonary Arteriovenous Malformations: Safety and Efficacy of Microvascular Plugs.

The purpose of this study is to assess the safety and efficacy of microvascular plugs for the treatment of pulmonary arteriovenous malformations (PAVMs). From July 2014 to March 2017, 22 consecutive patients with hereditary hemorrhagic telangiectasia underwent treatment of PAVMs using microvascular plugs. The number, location, and type (simple or complex) of PAVM and the diameter of the feeding artery were assessed at angiography. Safety was evaluated by successful detachment and absence of migration of the microvascular plug after deployment. Efficacy was assessed by technical success, defined as immediate stasis in the feeding artery above the microvascular plug at the time of angiography, and by the persistence rate at 1-year follow-up CT. Thirty-nine PAVMs (36 simple and three complex) were treated with 52 microvascular plugs in 22 consecutive patients. Thirty-three PAVMs were undergoing initial treatment and six were undergoing retreatment after previous embolotherapy. All microvascular plugs were successfully detached. No microvascular plug migration was observed. The mean (± SD) feeding artery diameter was 2.3 ± 0.7 mm. Technical success was achieved for 51 of 52 (98%) microvascular plug deployments. Follow-up CT, which was available for 20 of 22 (91%) patients, with a mean delay of 12.6 ± 3.1 months, showed two persistent PAVMs (persistence rate, 6%), one due to recanalization through the microvascular plug and the other due to reperfusion from an untreated adjacent pulmonary feeding artery. Microvascular plugs are safe and effective for treatment of PAVMs, with a low persistence rate (6%) 1 year after treatment.

3:54 PM Abstract No. 107 Intermediate-term results of the microvascular plug (MVP) for treatment of pulmonary arteriovenous malformations

To evaluate intermediate-term results for embolotherapy of pulmonary arteriovenous malformations (PAVMs) using the Micro Vascular Plug (MVP). Patients with HHT and PAVMs treated by MVPs between October 2014 and January 2017 were retrospectively reviewed. Data collected included age, gender, number and type of PAVM, feeding artery size, device migration, aneurysmal sac size and perfusion. Technical success was defined as immediate intraprocedural angiographic occlusion of the feeding artery beyond the plug. Successful intermediate-term treatment was defined in 2 ways: 1. No sac enhancement (no perfusion of the PAVM sac on follow-up contrast-enhanced CT), and 2. No persistence (> 70% reduction in PAVM sac diameter on latest available CT). MVP-3, 5, 7 and 9 were chosen to embolize feeding arteries measuring < 3, 3-5, 5-7, and 7-9 mm respectively. One hundred and twenty-two MVPs (91 MVP-3, 28 MVP-5, 2 MVP-7, and 1 MVP-9) were deployed in 106 PAVMs (82 simple, 24 complex). Average feeding artery size was 2.6 mm (1.1-7.1 mm). Immediate technical success was achieved in 115 of 122 (94%) deployments. CT was available for 19 patients (18 female, 11 male) with 67 treated PAVMs with an average age of 41. Average latest available CT follow-up.: 14.6 months (range, 5.6-38.8). There was no enhancement of the PAVM sac on CECT in 63 of 67 (94%) PAVMs. No persistence was seen in 50 of 67 PAVMs (75%). There were 2 complications: One migration occurred when a MVP-5 placed in a 5 mm feeding artery migrated to the draining vein on 3 mo follow-up CT requiring re-embolization. One patient developed a toe microemboli after delayed electrolytic detachment. Our series of 106 PAVMs treated with 122 MVPs demonstrated a high rate of immediate angiographic occlusion, and successful treatment on intermediate follow-up CT with an average follow-up of 14.6 months. The MVP should be oversized beyond manufacturer recommendations to prevent migration, particularly when the draining vein is large.Tabled 1Feeding Artery Size Embolized with the MVPFeeding Artery DiameterMVP-3MVP-5MVP-7MVP-9Ave (mm)2.14.15.07.1Range (mm)1.1-3.03.0-5.04.2-5.8n/aTotal912821 Open table in a new tab

3:45 PM Abstract No. 106 Comparing solid embolic devices for the embolization of pulmonary arteriovenous malformations: an update

Accepted practice is to treat all PAVMs greater than 2-3 mm using transcatheter embolization in order to prevent paradoxical emboli, aneurysm rupture, and chronic hypoxemia secondary to shunting. Though multiple solid embolic devices have been used to occlude PAVMs, coils remain the most commonly used despite recanalization rates as high as 15%. An alternative to coils is the Amplatzer Vascular Plug and the MicroVascular Plug System which allow for the occlusion of small feeding vessels with a single device. We compared these three embolic devices for the treatment of PAVMs specifically investigating procedural attributes, outcomes, and costs. We performed an IRB approved retrospective review on all patients with PAVM treated exclusively with coils, AVP or MVP between October 2014 and July 2016. Procedural attributes, costs, and recanalization rates were collected and compared. Technical success was defined as complete occlusion of the feeding artery supplying the PAVM. Recanalization and revascularization were assessed by routine clinical follow-up and confirmed using CT angiography of the chest. A total of 68 patients with 102 PAVMs treated in 72 procedures were included. All procedures were technically successful without any minor or major complications. Multiple Regression was used to assess the association between clinical outcomes, adjusting for patient age, sex, HHT status, total AVMs treated per session, and mean feeding artery diameter. There was no significant difference between procedural time, fluoroscopy time, and contrast administered between our three groups. In terms of cost of embolic per procedure AVP was 69% cheaper than coils (95% CI 59-76% p <0.0001) and 50% cheaper MVP (95% CI 38-60% p <0.0001). MVP was 37% cheaper than coils (95% 14-54% p = 0.0038). Recanalization rates: Coils 15% with average follow-up of 597 days; AVP 7% with average follow-up of 481 days; MVP 0% with an average follow-up of 235 days. Transcatheter embolization using solid embolics is safe and effective. Based on our analysis AVP is the most cost effective embolic with a lower rate of recanalization when compared to coils. MVP demonstrated the lowest recanalization rate.

Arterial embolizations with microvascular plug in extracranial and intracranial districts: technical results.

A new detachable microvascular plug (MVP, Reverse Medical®, Irvine, CA, USA) has been recently developed; three models are available according to the size (MVP3-MVP5-MVP7). MVP3 and MVP5 are released through a 0.027″ microcatheter, MVP7 through a 4Fr catheter. This series aims to describe an initial single-center experience examining intraprocedural safety and technical success of MVP. Ten patients (mean age 55.1years) have been treated for arterial embolization using MVP; eight extracranial and two intracranial arterial embolizations have been performed. The embolizations were because of: four bleedings, three aneurysms, two pseudoaneurysms, and one presurgical nephrectomy. MVP3 was used in five cases, MVP5 in four cases, and MVP 7 once. In all cases, the MVP was successfully released in<1min. In six patients, the MVP was the sole embolizing agent employed, while in four subjects, it was positioned complementary after coils. The technical and clinical success was obtained in 100%; hemorrhages were interrupted and aneurysms and pseudoaneurysms did not show recanalization at follow-up. MVP seems to be a safe embolizing device that interventional radiologists should consider when facing arterial embolization of both body and neuroarterial districts; the main advantage is related to MVP3 and MVP5 models that can be adopted for distal embolization thanks to the precise release through 0.027″ microcatheter.

Use of a Polytetrafluoroethylene-Coated Vascular Plug for Focal Intracranial Parent Vessel Sacrifice for Fusiform Aneurysm Treatment.

Fusiform intracranial aneurysms are challenging due to the circumferential nature of the disease. Endovascular parent vessel sacrifice with coils may be a treatment option, but typically requires a long vessel segment to induce complete cessation of flow. We evaluate early clinical experience with the intracranial use of the microvascular plug (MVP; Medtronic, Dublin, Ireland) device and to compare to previous coil-only techniques for vertebral artery sacrifice for fusiform vertebral aneurysm. We reviewed patients treated with the MVP for intracranial aneurysms at our institution. As a case-control study, we located 6 control patients who underwent coiling alone for vertebral artery sacrifice. The number of implants, fluoroscopy time, and procedural charges were compared using unpaired t -tests. Twelve patients underwent vessel sacrifices with MVP. Eight were for vertebral artery dissecting aneurysms. Comparing only vertebral aneurysms, the mean implants was 7 in the MVP group (n = 8) and 19.5 in the coiling group (n = 6; P = .0015). Mean fluoroscopy time was 17.62 min in the MVP group compared to 24.2 min in the coiling group ( P = .07). Procedural costs were less in the MVP group ($19 667.38) compared to coiling ($44 909.50, P = .05). There were no technical failures and no cases with persistent flow in the parent vessel at the end of the procedure. The MVP is a cost-effective device for focal intracranial vessel occlusion in select patients. This is an important tool for cerebrovascular surgeons, particularly in cases of ruptured dissecting vertebral aneurysms.

Bleeding ectopic duodenal varix: use of a new microvascular plug (MVP) device along with transjugular intrahepatic portosystemic shunt (TIPSS)

Ectopic varices (ECV) occur along the gastrointestinal (GI) tract outside the common variceal sites and represent 2%–5% of all GI variceal bleeds with mortality rates up to 40%. Management is...

Abstract No. 504 - Microvascular plug embolization of the gastroduodenal artery during hepatic artery skeletonization: our initial experiences in 34 patients

Abstract No. 504 - Microvascular plug embolization of the gastroduodenal artery during hepatic artery skeletonization: our initial experiences in 34 patients

Pulmonary Arteriovenous Malformations Embolized Using a Micro Vascular Plug System: Technical Note on a Preliminary Experience.

To report our preliminary experience using a Micro Vascular Plug (MVP) deployed through a 2.8Fr micro-catheter for the treatment of pulmonary arteriovenous malformations (PAVMs) in a cohort of patients affected by Hereditary Haemorrhagic Telangiectasia (HHT). Four consecutive female patients (mean age 38.0years; range 25-55years) with PAVMs diagnosed on echocardiogram/bubble test and contrast-enhanced CT (CECT) underwent MVP embolization. One patient was symptomatic with recent transient ischaemic attack. Follow-up was undertaken at 1-month post-procedure with CECT to assess PAVMs permeability and MVP positioning and at 1-, 6-, and 12-month post-procedure, with echocardiography/bubble test and standard neurological history, to confirm absence of right-to-left shunts and recurrent symptoms. Eight PAVMs were treated in 4 patients over 5 interventional sessions (mean 1.6 PAVMs per session). All PAVMs were simple, with mean feeding artery diameter of 4.25mm. Eight 6.5mm MVPs were deployed in total (one per lesion). Technical success was 100%. Mean procedural time and patient dose per session were 70min (range 40-70min) and 53418mGy.cm2 (range 6113-101628mGy.cm2), respectively. No signs of reperfusion neither of MPV migration were noted at 1-month CECT follow-up. At early follow-up (mean 3.75months; range 1-12months), clinical success was 100% with no evidence of recurrent right-to-left shunt, and no neurological symptoms. No immediate or late complications were observed. MVP embolization of PAVMs appears technically feasible, safe, and effective at early follow-up. Further prospective studies are required to confirm long-term safety and efficacy of this promising technique.

Occlusion of Small Arteries in the Neuroendovascular and Head and Neck Territory—Initial Experiences with a Microvascular Plug

The microvascular plug (MVP, UNO; Reverse Medical Corp, Irvine, California) is designed for occlusion of small vessels that are accessible only by microcatheters. This report describes eight neuroendovascular cases, including aneurysms and acute or imminent hemorrhage, treated with 10 microvascular plug devices. Instantaneous flow arrest was observed in all but two cases, in which the device was undersized, requiring supplementary coiling or microvascular plug replacement, respectively. Persistent occlusion was confirmed on follow-up examinations. There was one adverse event, which involved inadvertent device detachment after repeated resheathing. The microvascular plug appears to be suitable for the designated purpose. Further studies need to evaluate safety and confirm long-term durability of the results.

Micro Vascular Plug (MVP)-assisted vessel occlusion in neurovascular pathologies: technical results and initial clinical experience

BackgroundDeconstructive approaches may be necessary to treat a variety of neurovascular pathologies. Recently, a new device has become available for endovascular arterial occlusion that may have unique applications in neurovascular...

O-027 Micro Vascular Plug (MVP) Assisted Vessel Occlusion in Neurovascular Pathologies: Technical Results and Initial Clinical Experience

PurposeEndovascular vessel occlusion may be necessary to treat a variety of neurovascular pathologies such as pseudo-aneurysms and giant aneurysms, iatrogenic and penetrating vascular injuries and direct arteriovenous fistulas of the...

Microvascular plug: a new embolic material for hepatic arterial skeletonization.

Arterial skeletonization before radioembolization or hepatic artery port catheter placement for chemotherapy is a crucial step to prevent side effects. Coils are commonly used as an embolic material for hepatoenteric arterial occlusion. Herein is reported for the first time the clinical use of a new detachable microvascular plug (MVP) suitable for occlusion of 1-3 mm diameter vessels. The MVP allows vessel embolization even in challenging anatomy such as the right gastric artery. Furthermore, immediate and stable vessel occlusion was observed in our pilot study of 16 MVP placements.