The Amplatzer vascular plug

Glue in Lockdown Technique to Embolize Peripheral Arterial Aneurysms

As a blood flow control technique for embolization using glue (n-butyl cyanoacrylate; NBCA) for peripheral artery aneurysm/pseudoaneurysm, we placed a vascular plug or coils at the proximal inflow vessel before glue injection. We describe this maneuver, which we call the glue in lockdown technique. Four peripheral aneurysms-two pulmonary artery pseudoaneurysms, one pancreaticoduodenal arcade pseudoaneurysm, and one internal iliac artery aneurysm-deemed unsuitable for conventional embolization because of abnormal blood flow, coagulopathy, or anatomical complexity were embolized with our technique. Technical and clinical outcomes were reviewed to evaluate the effectiveness of the procedure. Reliable and rapid embolization was achieved in coagulopathy cases and hemodynamically or anatomically complicated lesions. Glue in lockdown technique was successfully used to treat peripheral aneurysms and can be further developed for application to other lesions.

Preloading Coil in Plug Method (p-CIP) with the AVP 2 for large Portosystemic Shunt Embolization

Hepatic encephalopathy caused by a large portosystemic shunt (PSS) can be treated by endovascular embolization of the shunt. The PSS diameter can be >20 mm; it occasionally poses technical difficulties. Here, a 72-year-old woman with liver cirrhosis, hyperammonemia, and large spleno-renal shunt underwent shunt embolization using an Amplatzer vascular plug 2 (AVP2) and metallic coils. The preloading coil in plug method (p-CIP), which facilitated embolization inside the AVP2 without cannulation from outside, was employed to overcome technical difficulties. We propose the use of p-CIP with an AVP2 as a tool for treatment of hepatic encephalopathy with PSS.

Meta-analysis of Intraprocedural Comparative Effectiveness of Vascular Plugs Vs Coils in Proximal Splenic Artery Embolization and Associated Patient Radiation Exposure

PURPOSE

To compare vascular plugs to coil embolization of the proximal splenic artery and evaluate differences in radiation exposure to the patients.

METHODS

An electronic literature search was performed for relevant studies from January 2000 to July 2018 that compared the efficacy of vascular plugs vs coils in splenic artery embolization. Only studies that investigated coil or vascular plug use, without combination with other embolic agents, were included. Meta-analysis was performed using a fixed effects model approach with the inverse variance-weighted average method to determine pooled differences in time to vessel occlusion, procedure time, fluoroscopy time, total number of devices used, and radiation exposure. Heterogeneity was assessed using the I square statistic. Pooled outcomes were compared, and quality assessments were evaluated using the Newcastle Ottawa Scale.

RESULTS

Eight studies met inclusion criteria. 81 patients were embolized with vascular plugs and 52 patients with coils only. The most common indication for splenic artery embolization was trauma. Time to vessel occlusion was shorter in the vascular plug group by 7.11 minutes (P = 0.003). Fluoroscopy time was shorter by 13.82 minutes in the vascular plug cohort, and these patients received less radiation (-439 mGy) compared to the coil group (P = 0.006 and P = 0.02, respectively). The number of devices was significantly fewer in the vascular plug group (-3.54; P < 0.001). Procedure time was not statistically significant.

CONCLUSION

Our data supports the vascular plug is superior to coils for embolization of the proximal splenic artery with respect to occlusion time, fluoroscopy time, patient radiation exposure, and number occlusive devices used.

Use of the Hourglass peripheral embolisation device: early experiences

We evaluated a novel intravascular plug, the Hourglass peripheral embolisation device (PED). We describe, for the first time, the use of this device and discuss its potential applications. The device was deployed in nine patients over a six-month period at a single institution by two different operators. Five patients underwent renal artery embolisation, three underwent gonadal vein embolisation for a varicocele, and a single patient underwent embolisation of the gastroduodenal artery. We recorded the indications, success rate, and the procedure-related complication rate in all patients. We also evaluated the satisfaction of the operators with the device using a post-procedure evaluation form. Technical success was achieved in 9/9 (100%) cases. Unanimous feedback was obtained from the operators (100% agreement). The usability of the delivery system, device deployment, and device visibility under fluoroscopy were rated as easy in 9/9 (100%) cases. The ease of repositioning was rated as good in both cases where this was attempted. The device trackability was rated as good in 9/9 (100%) cases. There were no procedure-related complications. The Hourglass PED is potentially useful for the embolisation of small-to-medium sized vessels.

Proximal embolization of splenic artery in acute trauma: Comparison between Penumbra occlusion device versus coils or Amplatzer vascular plug

PURPOSE

To compare intervention duration and fluoroscopy time for proximal embolization of splenic arteries in acute trauma using the Penumbra occlusion device (POD^®), coils or Amplatzer™ vascular plug (AVP).

MATERIAL AND METHODS

A total of 29 patients with splenic injury without vascular injury who were treated by proximal splenic artery embolization using POD^® (n=12), coils (n=9) or AVP (n=8) were retrospectively included. There were 25 men and 4 women with a median age of 34 years (range: 10-69 years). To overcome bias in treatment choice, a propensity score was used using inverse probability weighting. Intervention duration and fluoroscopy time, treatment success and complications were compared.

RESULTS

The median intervention duration was significantly shorter using POD^® (30min) or AVP (47min) than using coils (60min) (P=0.0001 and 0.004, respectively). The median fluoroscopy time was significantly lower using POD^® (11.5min) than using coils (23.6min) (P=0.0076) or AVP (16.5min) (P=0.049). The primary efficacy rate was 100% with POD^® and AVP and 89% with coils (P=0.586). Six complications occurred with a mean follow-up of 12 months for POD^®, 32 months for coils and 40 months for AVP, consisting in 2 abscesses treated by anti-biotherapy with POD^®, one abscess with AVP, 2 material migrations with coils and 1 coil dismantled without consequence.

CONCLUSION

POD^® and AVP allow proximal embolization of splenic artery in acute trauma with shorter intervention duration by comparison with conventional metallic coils with similar technical success. POD^® allows a shorter fluoroscopy time than coils or AVP.

The Amplatzer Vascular Plug: Review of Evolution and Current Applications

The Amplatzer Vascular Plug (AVP) was created for peripheral embolization as a modification of the family of Amplatz septal occluders used in the treatment of congenital heart malformations. The device has evolved over the years and multiple versions have been launched into the market. Each of the versions of the device has some important modifications in terms of the size of the introducer's system, number of layers, and resultant thrombogenicity. It is very important for the operator to become familiar with the unique features of the AVP, and to understand the advantages and limitations of each model in the AVP family to achieve an optimal embolic result. The purpose of this article is to review the evolution and current clinical applications of the AVP in the field of interventional radiology, with emphasis on the advantages and limitations of this device in comparison with other embolization agents.

Embolization of a giant arterioportal fistula requiring multiple Amplatzer vascular plugs

Arterioportal fistulas (APFs) are rare vascular communications between the mesenteric arterial tree and the portal vein. The causes and presentations of this entity are varied. APFs related to tumor, infection, and trauma have been described. Patients may be asymptomatic or present with hemobilia, portal hypertension, or mesenteric steal syndrome. Small APFs require no intervention, with treatment indicated for large or symptomatic APFs. The treatment has shifted from surgical ligation or hepatic resection to an endovascular-first approach. We describe an endovascular treatment option for the management of an acquired extrahepatic (type 2) APF and present a review of the literature.

Spinal cord involvement in patients with cirrhosis

A severe spinal cord involvement may rarely occur in patients with cirrhosis and other chronic liver diseases; this complication is usually associated with overt liver failure and surgical or spontaneous porto-systemic shunt. Hepatic myelopathy (HM) is characterized by progressive weakness and spasticity of the lower extremities, while sensory and sphincter disturbances have rarely been described and are usually less important. The diagnosis is assigned in the appropriate clinical setting on clinical grounds after the exclusion of other clinical entities leading to spastic paraparesis. Magnetic resonance imaging is often unremarkable; however, also intracerebral corticospinal tract abnormalities have been reported recently. The study of motor evoked potentials may disclose central conduction abnormalities even before HM is clinically manifest. HM responds poorly to blood ammonia-lowering and other conservative medical therapy. Liver transplantation represents a potentially definitive treatment for HM in patients with decompensated cirrhosis of Child-Pugh B and C grades. Other surgical treatment options in HM include surgical ligation, shunt reduction, or occlusion by interventional procedures.

Gelfoam-assisted amplatzer vascular plug technique for rapid occlusion in proximal splenic artery embolization

OBJECTIVE

The objective of this study was to prospectively investigate the role of rapid Gelfoam-assisted occlusion of the splenic artery with an Amplatzer Vascular Plug (AVP). Ten consecutive proximal splenic artery embolizations were performed with AVP as the primary embolic agent and Gelfoam slurry as an adjunct. These cases were then compared with 10 retrospective cases of splenic artery embolization performed with AVP and augmented with coils or additional AVPs, or both, in patients with similar indications.

CONCLUSION

Successful proximal splenic artery embolization using a single Amplatzer Vascular Plug and Gelfoam slurry occurred in all cases. No recanalization was identified on imaging follow-up at an average interval of 5.1 months. Gelfoam can be used as an adjunct to AVP in proximal splenic artery embolization. Using adjunctive Gelfoam is a simple, safe, and cost-saving method of improving the occlusion efficiency of the Amplatzer Vascular Plug.

Management of surgical splenorenal shunt-related hepatic myelopathy with endovascular interventional techniques

We present a case with hepatic myelopathy (HM) due to a surgical splenorenal shunt that was successfully treated by endovascular interventional techniques. A 39-year-old man presented with progressive spastic paraparesis of his lower limbs 14 mo after a splenorenal shunt. A portal venogram identified a widened patent splenorenal shunt. We used an occlusion balloon catheter initially to occlude the shunt. Further monitoring of the patient revealed a decrease in his serum ammonia level and an improvement in leg strength. We then used an Amplatzer vascular plug (AVP) to enable closure of the shunt. During the follow up period of 7 mo, the patient experienced significant clinical improvement and normalization of blood ammonia, without any complications. Occlusion of a surgically created splenorenal shunt with AVP represents an alternative therapy to surgery or coil embolization that can help to relieve shunt-induced HM symptoms.

Splenic artery syndrome after orthotopic liver transplantation: treatment with the Amplatzer vascular plug

PURPOSE

To evaluate the safety and efficacy of the Amplatzer vascular plug (AVP) for embolization of the splenic artery in patients with hepatic hypoperfusion after orthotopic liver transplantation (OLT).

MATERIALS AND METHODS

Thirteen patients (9 men and 4 women) with a mean age of 56 years (range 22-70) who developed splenic artery syndrome after OLT with decreased liver perfusion and clinically relevant impairment of liver function (increased transaminase or serum bilirubin levels, thrombocytopenia, and/or therapy-refractory ascites) were treated by embolization of the proximal third of the splenic artery using the AVP. The plugs ranged in diameter from 6 to 16 mm, and they were introduced through femoral (n = 9), axillary (n = 3), or brachial (n = 1) access using a 5F or 8F guiding catheter.

RESULTS

The plugs were successfully placed, and complete occlusion of the splenic artery was achieved in all patients. Placement of two plugs was necessary for complete occlusion in 3 of the 13 patients. Occlusion took on average 10 min (range 4-35). There was no nontarget embolization or plug migration into more distal segments of the splenic artery. All patients showed improved arterial perfusion, including the liver periphery, on postinterventional angiogram. After embolization, liver function parameters (transaminase and bilirubin levels) improved with normalization of concomitant thrombocytopenia and a decrease in ascites volume.

CONCLUSION

Our initial experience in a small patient population with SAS suggests that the AVP enables precise embolization of the proximal splenic artery, thus providing safe and effective treatment for poor liver perfusion after OLT due to SAS.

Endovascular repair of isolated iliac artery aneurysms

PURPOSE

To retrospectively evaluate a 12-year experience with endovascular repair of isolated iliac artery aneurysm (IAA).

METHODS

From August 1997 through July 2009, 91 patients (81 men; mean age 71 years, range 31-90) underwent endovascular treatment for isolated IAA at our department. Of these, 77 patients received stent-grafts either alone or in combination with coils or an Amplatzer vascular plug (n = 2); 1 patient received a Smart stent combined with coils, and 13 patients were treated with coil embolization only. The aneurysms were classified according to location: type I = common iliac artery (CIA), type II = internal iliac artery (IIA), type III = CIA and IIA, and type IV = external iliac artery with/without CIA and/or IIA involvement.

RESULTS

Primary technical success was 90.1% for all aneurysm types and 93.6%, 80%, 88.8%, and 93.3% for types I, II, III, and IV, respectively. Secondary technical success was 96.7% for all types and 97.8%, 95%, 100%, and 93.3%, respectively, for each type. Clinical success was 93.4% for all types and 97.8%, 85%, 100%, and 86.7%, respectively, by type. Complications in 18 (19.8%) patients included 7 type I endoleaks, 3 type II endoleaks, 2 enlarged aneurysm sacs (incomplete embolization), 5 cases of buttock claudication, and 2 stent-graft thromboses. Two patients were converted to open surgery; 10 underwent secondary interventions. Mortality rates were 1.1% (n = 1) at 30 death days and 23.1% (n = 21) over a mean follow-up of 45.9 months (no aneurysm-related death). Cumulative overall survival was 97.7% at 1 year and 47.6% at 10 years. Freedom from aneurysm-related complications was 88.6% at 1 year and 83.5% at 5 years.

CONCLUSION

Endovascular repair of isolated IAA is a safe and minimally invasive alternative to surgery. However, it may be associated with several complications and must, therefore, be carefully planned.

Utility of the Amplatzer Vascular Plug in splenic artery embolization: a comparison study with conventional coil technique

PURPOSE

To retrospectively evaluate the role of the Amplatzer Vascular Plug (AVP) in proximal splenic artery embolization (SAE) compared with coils.

MATERIALS AND METHODS

Forty patients had proximal SAE performed with AVP(s) or coils as the primary embolic agent for splenic artery steal syndrome (n=23), trauma (n=5), portal hypertension (n=5), bleeding due to pancreatic pathology (n=4), and pre-splenectomy (n=3). Comparisons were made of occlusion and procedure time, cost, and radiation dose.

RESULTS

Eighteen proximal SAE procedures were successfully performed with AVP. Twenty-two procedures were performed with coils, including one failed AVP attempt, which was completed with coils. Precise deployment without migration was achieved in all 18 AVP cases. Seven of 22 (31.8%) coil procedures had distal migration without consequence. There was no statistically significant difference in mean occlusion time (24.4 min for AVP vs. 31.5 min for coils, P=0.13), procedure time (43.7 min for AVP vs. 53.8 min for coils, P=0.16), or cost ($1474.13 for AVP vs. $1722.51 for coils, P=0.69). There was significant difference in radiation dose (842 mGy for AVP vs. 1,309 mGy for coils, P=0.04). Fourteen of the 18 (78%) AVP devices required additional embolic material.

CONCLUSIONS

AVP with additional embolic agents is a useful alternative for proximal SAE because of precise deployment, resistance to migration, and radiation reduction. AVP use may be limited by vessel tortuosity. The occlusion time, procedure time, and cost were reduced but this was not statistically significant due to the need for additional embolic material.

Successful embolization of a spontaneous mesocaval shunt using the Amplatzer Vascular Plug II

A 48-year-old man with alcoholic liver cirrhosis and hepatic encephalopathy was found to have a large, spontaneous mesocaval shunt. The shunt was successfully occluded with the use of an Amplatzer Vascular Plug. To our knowledge, this is the first report of the use of this device to embolize a mesocaval shunt involving the superior mesenteric vein.