Use of a steerable triaxial system for challenging catheterization

Arterial embolization via retrograde approach using steerable microcatheter and triaxial system

We report a case of postoperative pseudoaneurysm, successfully treated with selective arterial embolization, using a steerable microcatheter and triaxial system via retrograde approach. A pseudoaneurysm was detected in the dorsal pancreatic artery, a severely narrow and steeply inverted branch of the superior mesenteric artery, making microcatheter insertion via the antegrade approach challenging. However, a steerable microcatheter was advanced beyond the orifice and the tip was reversed, changing the route to retrograde allowing for easy insertion of the microguidewire. Subsequently, a small microcatheter was advanced beyond the pseudoaneurysm into the dorsal pancreatic artery, and arterial embolization was successfully completed without complications.

Steerable-wire technique using high-flow steerable microcatheter and 0.025-inch guidewire

A high-flow steerable microcatheter has been reported to be useful as a triaxial system. Moreover, the benefits of steerable microcatheters in acute-angle bifurcation vessel insertions and a compact coil-packing technique using intentional folding with a bendable catheter tip have been reported. However, research on the usefulness of a high-flow steerable catheter and 0.025-inch guidewire combination (steerable-wire) technique is lacking. Herein, we report a case of balloon-occluded retrograde transvenous obliteration (BRTO) via the femoral venous approach to illustrate the usefulness of the steerable-wire technique. The steerable-wire technique facilitates the selection of the wire into the target vessel. The steerable-wire can be used instead of the 0.035-inch guidewire, which is versatile as other devices can follow the steerable wire.

Antecubital vein approach of retrograde transvenous obliteration using a steerable triaxial system for portosystemic encephalopathy

We report a case of portosystemic encephalopathy treated by retrograde transvenous obliteration (RTO) with an antecubital vein approach using a steerable triaxial system. A 77-year-old female was referred to our department complaining of dizziness and tremor. Laboratory data showed hyperammonemia. Contrast-enhanced CT and 3D-CT reconstruction images demonstrated an inferior mesenteric vein (IMV)-left common iliac vein shunt and a splenorenal shunt. The former was treated as a responsible shunt. The spleen volume was 212 mL, and the liver volume was 757 mL; giving a spleen/liver volume ratio of 0.3. Partial splenic artery embolization (PSE) was employed to control portal venous pressure. The hepatic venous pressure gradient (HVPG) changed from 13.2 to 9.6 mm Hg and the spleen/liver volume ratio improved from 0.3 to 0.2 by PSE. Two months after PSE, RTO with an antecubital vein approach using a steerable triaxial system was performed. HVPG changed to 12.5 mm Hg after RTO. Contrast-enhanced CT and 3D-CT reconstruction images 3 days after the procedure demonstrated the thrombus in the IMV-left common iliac vein shunt. We conclude that the antecubital vein approach using a steerable triaxial system is a feasible and minimally invasive technique in RTO for portosystemic shunts.

New concept in neurovascular navigation: technical description and preclinical experience with the Bendit 17 and Bendit 21 microcatheters in a rabbit aneurysm model

BACKGROUND

Endovascular treatment of intracranial vascular diseases, such as aneurysms, is often challenged by unfavorable vascular anatomy. The Bendit Steerable Microcatheter (Bendit Technologies, Tel Aviv, Israel) has bending and torqueing capabilities designed to improve navigation and stability during device delivery, with or without a guidewire. We describe our preclinical experience with the Bendit 17 and Bendit 21 microcatheters in a rabbit aneurysm model.

METHODS

Bifurcation and side wall aneurysms were created surgically in six New Zealand rabbits. We attempted to navigate Bendit devices through the vasculature and enter the aneurysms without a guidewire. Various positions within the aneurysm were selectively explored. Angiographic imaging was used to visualize catheterization, navigation, vascular manipulations, and placement of coils, stents, and intrasaccular devices.

RESULTS

We successfully navigated the Bendit microcatheters to all aneurysms without a guidewire. We successfully recanalized a nearly occluded carotid artery and navigated the Bendit through a braided stent. In contrast, we were unable to navigate a comparator device with a guidewire as effectively as the Bendit. Coils were introduced at different locations within the aneurysm and could be pushed, pulled, and repositioned with the Bendit tip. Finally, we used the Bendit to deliver intrasaccular devices designed for terminal aneurysms to treat side wall aneurysms.

CONCLUSIONS

Bendit's bending and torqueing abilities, combined with its stability in the bent position, enable quick navigation and optimal deployment of devices. Clinical studies are necessary to determine whether these navigation advantages lead to more efficient treatment of intracranial and peripheral aneurysms.

Embolization using patient-specific vascular models created by a 3D printer for difficult cases: a report of two cases

With the widespread use of three-dimensional printers, organ models created by these printers are now being used in the medical field for preoperative planning of surgeries. In this article, we report two cases in which embolization was expected to be difficult, and the three-dimensional printer-based vascular modeling was helpful in planning the surgery. The first case involved an aneurysm of the splenic artery. We attempted to embolize the aneurysm but were unable to advance the catheter into the distal artery and discontinued the procedure. The second case was a perianal varicose vein, which was initially treated with percutaneous transhepatic obliteration but was recanalized and required embolization. However, we expected difficulty in selecting the inferior mesenteric vein. In both cases, the vascular models were created using a 3D printer from the patients' computed tomography images. Preoperative planning, including treatment simulation, was based on these models. The time required to print a three-dimensional vascular model was approximately 12 hours at a cost of less than $10 each. Patient-specific vascular models using a three-dimensional printer can be a simple and inexpensive tool that can increase the success of embolization in difficult cases.

Bleeding anorectal varices treated by a direct puncture approach through the greater sciatic foramen: The utility of a steerable microcatheter for reverse catheterization

Bleeding is less common from anorectal varices than from esophageal varices, but it is potentially life-threatening. Here, we present a case of a woman in her 70s with critical hemorrhage from anorectal varices. The endoscopic approach could not be performed due to the huge variceal formation and the transhepatic approach was also unsuitable due to the presence of portal vein thrombosis and ascites. A direct puncture to the right superior rectal vein was performed through the greater sciatic foramen under computed tomography fluoroscopic guidance. Using a steerable microcatheter, superior rectal veins were bilaterally embolized with a mixture of n-butyl cyanoacrylate and ethiodized oil, and microcoils. Endoscopy and contrast-enhanced computed tomography performed after the procedure confirmed a marked shrinkage of anorectal varices. When endoscopic or any other approaches are difficult, this technique can be a useful alternative therapeutic option.

A case of maxillary cancer treated by intra-arterial therapy using a steerable microcatheter

We report on a 69-year-old man with locally-advanced left maxillary sinus cancer who underwent treatment with intra-arterial chemoradiotherapy. Angiography showed that the main feeding arteries were the left maxillary artery and the ophthalmic artery, arising from the internal carotid artery. Due to acute branching of the ophthalmic artery, conventional microcatheters could not be inserted. Using a steerable microcatheter, we were able to repeatedly administer chemoradiotherapy via the ophthalmic artery. The tumor has mostly disappeared after intra-arterial chemoradiotherapy, and the patient is still alive two years after treatment. A steerable microcatheter is very useful for acute-angled vascular branches.