Figure 5A CTA and MIP CTA before embolization.

Figure 5B Angiogram dissecting aneurysm before embolization.

Figure 5C Angiogram after deployment of ArtVentive EOS 8 and 11mm plugs.

Figure 5D MIP CTA 2 months after embolization of a common hepatic and gastroduodenal artery dissecting aneurysm with ArtVentive EOS 8 and 11 mm plugs (arrow).

First Experiences with a New Vascular Occlusion Device: The ArtVentive Endoluminal Occlusion System

A. The, MDDepartment of Radiology | Erasmus Medical Center RotterdamCorresponding e-mail: a.the@erasmusmc.nl | Disclosures: none

a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a

a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a

Introduction

Depending on the application, endovascular occlusion of vessels may require coils, glue, and/or metallic plugs. Occlusion should be complete and, in case of emergencies such as abdominal bleeding in blunt trauma, immediate after deployment of the occlusive devices. Devices may be detachable (e.g. an Amplatzer plug or detachable coils) or non-detachable, and devices may be immediately occlusive (e.g. glue), or do occlude only with a certain unintended delay. Preferably, embolization is performed with a detachable device that occludes immediately. In this poster presentation, we report on the application of a new endovascular occlusion system (EOS) for complete, immediate and permanent occlusion of peripheral vasculature.

Design and deployment of the EOS

A new device was used in this study: the ArtVentive EOS (ArtVentive Medical Group Inc, Carlsbad, CA, USA). This plug combines a nitinol scaffold with an ultrathin impermeable ePTFE membrane (Figure 1). The scaffold offers sufficient radial force for vessel wall apposition to minimize migration after deployment in both arterial and venous trajectories. The plug comes pre-loaded onto a delivery catheter that can be advanced through a guiding catheter with an inner diameter of at least 0.067”. The device is applicable in vessel diameters ranging from 3 to 11 mm using different sizes. These are nominal vessel sizes, no need for oversizing.

After catheterization towards the vessel trajectory that needs to be occluded, the guiding catheter should be advanced into the location of interest. The guiding catheter is left in place and the guide-wire is removed. Next, the side port of the device (Figure 2) should be flushed with (heparinized) saline.

Next, the device is backloaded into the guiding catheter and advanced towards the distal end of the guiding catheter. The guiding catheter is then retracted while the EOS plug is held in place. The plug is now exposed to the vessel. For deployment, the yellow clip is removed to unlock the device. The proximal handle is pulled and the ePTFE membrane and nitinol scaffold are released into the vessel. Deployment must be assisted by firm manual injection of saline and contrast agent mixed 70/30 injected through the flush port of the delivery catheter. To detach the plug from the delivery system, the blue clip is removed and the distal handle is pulled. After removing the delivery system, a contrast injection through the guiding catheter is performed to assess the vessel patency and to confirm total occlusion.

Applications

We treated various pathologies with this newly developed EOS (currently over 15 cases). The indications include both high-flow and low-flow vascular trajectories such as: portal vein embolizations and additional hepatic vein before hemihepatectomy, pre-operative metastasis embolization of a brachial artery branch, common hepatic artery aneurysm embolization, splenic artery embolization in trauma and aneurysm, ovarian vein embolizations in pelvic congestion syndrome and lung AVM’s. In all cases, the device could be positioned and deployed in the required position. The plug was clearly visible under fluoroscopy before and after deployment. Occlusion was immediate and complete in all cases. We encountered no complications. In one portal vein embolization case, the plug was slightly undersized and subsequently moved more distally, however without sequelae and complete occlusion was still achieved. In 10 cases, follow-up CT was available and showed permanent occlusion of the target vessel.

Figure 1: ArtVentive EOS plug

composed of an ePTFE layer and

spiral nitinol scaffold (P=proximal

site, D=distal site)____________________________________________________

Figure 2: ArtVentive EOS

delivery system (see text

for deployment details).___________________________________________________

Case 1: Portal vein embolization (before hemihepatectomy)

A 47y old female presents with history of biliary liver cirrhosis in which a large cholangiocarcinoma developed. The MRI depicts an irregular lesion in the right liver lobe with several satellite lesions. The lesion was hyperintense on T2, iso- to hypointense on T1 and caused capsular retraction. After gadolinium administration, the lesion showed peripheral enhancement (Figure 3A) with gradual enhancement in late phases, all of which is consistent with cholangiocarcinoma. Only surgery with a right sided liver resection was considered a curative option, preceded with a right portal vein embolization to induce left liver lobe hypertrophy.

To this end, the right portal vein was punctured with a Chiba needle and an 8 Fr 55 cm sheath was introduced in the portal vein under propofol sedation. A portogram (Figure 3B) was acquired and the embolization was performed using regular coils and an ArtVentive EOS plug (Figure 3C). The follow-up CT 6 weeks after the portal embolization showed complete occlusion of the right portal vein. The left liver hypertrophy was sufficient to permit a right hemi-hepatectomy and the patient went for surgery.

Case 2: Ovarian and internal iliac vein embolization (in pelvic congestion syndrome)

73y old female presents with lower abdominal pain on the left side classified as pelvic congestion syndrome. A long 6Fr sheath was placed in the right internal jugular vein. A diagnostic venography was performed with evaluation of both ovarian, internal iliac and external iliac veins. The venogram showed varices from the left ovarian and internal iliac vein. The left ovarian and internal iliac veins were selectively catheterized and were embolized using a combination of Aetoxyskerol, ArtVentive EOS plugs and coils. Post embolization venogram showed complete occlusion.

Case 3: Preoperative embolization of bone metastasis from HCC

A 73y old male with generalized bone metastases from hepatocellular carcinoma suffered from a pathologic fracture of the left upper extremity (Figure 6A). For stabilization of the fracture, the patient needed prosthetic nail and pin implementation. Because of the highly vascular nature of this tumor, a preoperative embolization was performed. A 6 Fr sheath was placed in the right common femoral artery and the left subclavian artery was catheterized under heparin. Using a 260 cm stiff wire, the catheter was exchanged for a 6Fr guiding catheter. The angiogram showed an arterial tumor blush in the left humeral shaft (Figure 6B). A large feeding vessel contributed to most of the tumor enhancement was selectively catheterized and a 5mm ArtVentive EOS was placed. Immediate hemostasis was acquired (Figure 6C).

Case 4: Embolization of a complex dissecting aneurysm arising from the celiac, common hepatic and gastroduodenal artery

60y old male presented with recurrent upper abdominal pain with a history of a complex dissecting aneurysm arising from the celiac, common hepatic and gastrodudodenal artery. A follow up CT scan showed slightly growth of the aneurysm. (Figure 5A). After multidisciplenary consultation we decided to treat the aneurysm. A 7Fr sheath was placed in the right common femoral artery and the hepatic artery was catheterized through the false lumen (Figure 5B). At first a side branch of the proper hepatic artery was coiled. Subsequently the aneurysm was excluded with an 8 mm and 11 mm ArtVentive EOS plug (Figure 5C). A small remaining aneurysm was left untreated. Patent circulation of the right and left hepatic artery was maintained through collateral filling from the left gastric artery. Follow up CT after 2 months showed near complete exclusion of the aneurysm with an unchanged small dissecting aneurysm of the celiac artery remaining (Figure 5D).

Case 5: “Appleby-procedure” in pancreatic neoplasia A 62y old female suffered a malignancy of the pancreas (Figure 7A) with encasement of the celiac trunk (TC). As previously proposed by Appleby et al., en bloc resection of the TC, along with the celiac nervous plexus and lymph nodes for malignancies of the pancreatic body, may be a curative surgical treatment. Because abrupt resection of the TC together with the common hepatic artery (CHA) may result in liver ischemia, a pre-surgical embolization of the CHA was performed, enabling hypertrophy of the collateral circulation from the superior mesenteric artery (SMA) to the left and right hepatic arteries (LHA and RHA).

Initial angiography of the TC (Figure 7B), demonstrates minor aberrant anatomy of the hepatic arteries with the LHA arising from the CHA before the gastroduodenal artery (GDA). Using a stiff guidewire with the tip in the GDA, a long braided 7 Fr sheath was introduced in the CHA. Next, an ArtVentive 8 mm EOS was placed just before the origin of the LHA (Figure 7C). The angiogram showed direct occlusion of the CHA. Angiography of the SMA showed collateral ow to the hepatic arteries with a slightly deep position of the plug in the CHA, but with sufficient to the LHA (Figure 7D).Figure 4A CT showing

varicose pelvic veins.Figure 4D Venogram of the left ovarian vein.

Figure 7A: Locally advanced pancreatic carcinoma with encasement of the celiac trunc.

Figure 7C: Complete occlusion of the common hepatic artery with an 8 mm plug.

Figure 7B: Angiogram of the TC and branches (LHA=left hepatic artery, RHA=right hepatic artery, CHA=common hepatic artery, GDA=gastroduodenal artery).

Figure 7D: Angiogram of the SMA demonstrates sufficient circulation to the hepatic arteries.

Figure 3A: T1-post-contrast MRI with a large cholangiocarcinoma in the right liver lobe.

Figure 3C: Embolization with regular coils and an ArtVentive EOS 11 mm plug (arrow).

Figure 3B: Portogram before embolization.

Figure 3D: Deployed EOS plug on follow-up CT. Some scattering due to coils close to the EOS.

Figure 6A: Pathological fracture at the left proximal humeral due to HCC metastasis. Figure 6C: Successful

embolization with EOS (*).

Figure 6B: Tumor blush predominantly from one large feeding artery.

Figure 4E Venogram after injection of Aetoxyskerol and deployment of ArtVentive EOS plug more proximal (arrow).

ConclusionsWe successfully applied the ArtVentive EOS in various vessel trajectories as mentioned above. Other applications are spermatic vein, iliac artery (prior to, or during, EVAR procedures) and gastroduodenal artery (e.g. hemorrhage, aneurysms, fistulae) embolizations. The main features of the device are its ability to immediate and reliably occlude the target vessels. These features might potentially save operation time, number of devices used for a single procedure and therefore reduce radiation exposure and use of contrast agent. Sizes larger than 11 mm should become available to extent its applications.

RPVLHA

CHA

GDA

Figure 4C Venogram after deployment of 2 ArtVentive EOS plug and coils.

Figure 4B Venogram of the left internal iliac vein with varicose pelvic veins.