Balloon Blocking Technique (BBT) for Superselective Catheterization of Inaccessible Arteries with Conventional and Modified Techniques

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.

Folded-Loop Guidewire Remodeling Technique: Catheterizing Markedly Angulated Branches during Intravascular Embolization

Purpose

Practical challenges are encountered in percutaneous intravascular procedures when applied to markedly angulated branching vessels. Herein, we introduced a folded-loop guidewire remodeling technique-the guidewire-shaping technique-to overcome difficult catheterization.

Materials and Methods

First, the tip of a 0.014-inch micro-guidewire was manually shaped like a pigtail loop. Second, the shaped guidewire was introduced into the microcatheter and was preloaded into the hollow metal introducer for suitability with the microcatheter hub. Gentle rotation of the guidewire after release from the microcatheter can create the preshaped pigtail loop configuration. On pulling back, the loop loosened, the configuration was changed to a small U-shaped tip, and the guidewire tip was easily introduced into the target artery.

Results

Between December 2019 and January 2022, the described technique was used in 64 patients (male/female, 49/15; mean age, 66.8 ± 9.5 years) for selective arterial embolization, after failed attempts with the conventional selection technique. The technique was successful in 63/64 patients (98%). The indications of embolization include transcatheter arterial chemoembolization, gastrointestinal bleeding, hemoptysis, trauma-induced bleeding, and tumor bleeding.

Conclusion

The folded-loop guidewire remodeling technique facilitates the catheterization of markedly angulated branching arteries; when usual catheterization method fails.

Selection of the right inferior phrenic artery using a dual-lumen microcatheter in transarterial chemoembolization for hepatocellular carcinoma

An 88-year-old woman with a history of multiple hepatocellular carcinomas (HCCs) presented with a new HCC in segment seven of the liver. We decided to perform transarterial chemoembolization for HCC. During treatment, the HCC was supplied by the right inferior phrenic artery (IPA), which originated from the proximal part of the left gastric artery with a steep bifurcation angle. Due to the very short distance between the origins of the left gastric artery and right IPA, the microguidewire and microcatheter were unstable in the left gastric artery and easily prolapsed into the celiac artery. Although different types of microcatheters were used, the right IPA could not be selected. Therefore, we used a dual-lumen microcatheter (DLM) to select the right IPA. The DLM stabilized the microguidewire in the left gastric artery, and the right IPA was successfully selected. Subsequently, transarterial chemoembolization was administered using a branch of the right IPA. Given this experience, we will consider using a DLM as an alternative method for selecting an abdominal artery when other techniques are unsuccessful.

Increasing Yttrium-90 Dose Conformality Using Proximal Radioembolization Enabled by Distal Angiosomal Truncation for the Treatment of Hepatic Malignancy

PURPOSE

To evaluate safety and feasibility of improving radiation dose conformality via proximal radioembolization enabled by distal angiosomal truncation where selective administration was not practical.

MATERIALS AND METHODS

Hepatic malignancies treated via angiosomal truncation between January 2017 and March 2019 were retrospectively evaluated. Thirty-three patients (8 women, 25 men; mean age, 62.2 y; range, 36-78 y) underwent 39 treatments. Of treatments, 74.3% (n = 29) were for hepatocellular carcinomas, 10.2% (n = 4) were for cholangiocarcinomas, and 15.4% (n = 6) were for metastatic tumors (1 colorectal adenocarcinoma, 1 pancreatic adenocarcinoma, 3 melanomas, and 1 endometroid carcinoma). Truncation was achieved using temporary embolic devices including a microvascular plug, detachable coil, gelatin slurry, and balloon microcatheter, after which proximal radioembolization was performed. Range of treatment activity was 0.47-5.75 GBq. Technetium-99m macroaggregated albumin and bremsstrahlung single photon emission computed tomography (CT)/CT threshold analysis was conducted to delineate and compare distribution of activity within the treatment angiosome before and after radioembolization.

RESULTS

Dosimetric analysis of 14 patients demonstrated a significant reduction in nontarget liver radiation exposure at 5, 20, and 40% thresholds (P = .002, P = .001, and P = .008, respectively). There were no grade 3 or higher adverse events. There was no significant change in Albumin-Bilirubin grade and Eastern Cooperative Oncology Group Performance Status (P = .09 and P = .74) before and 3 months after the procedure. Truncated arteries were patent on subsequent angiography in 11 cases and on MR angiography or CT angiography in 38 of 39 cases.

CONCLUSIONS

Proximal radioembolization enabled by distal angiosomal truncation is safe and decreases nontarget parenchymal radioembolization dose in cases not amenable to selective administration.

WEB as a combined support and embolization device in a giant partially thrombosed donut-shaped aneurysm

BACKGROUND

Giant partially thrombosed aneurysms are challenging lesions for which treatment can be difficult due to their unfavourable anatomical configuration and abnormal flow conditions.

CASE DESCRIPTION

The patient presented in this report suffered from a symptomatic giant partially thrombosed donut-shaped aneurysm of the left-sided supraophthalmic internal carotid artery. Due to the location and the size of the aneurysm, endovascular treatment was performed. Navigation of the microcatheter-microwire-system distal to the aneurysm for stent deployment was technically not possible due to limited support, caused by the large aneurysm. Therefore, a WEB device was placed in the distal leg of the donut-shaped aneurysm. Additionally to the occlusion of this part of the aneurysm, the WEB device enabled enough support to navigate the microcatheter-microwire-system distal to the aneurysm. After deployment of a flow-diverting stent, coiling of the aneurysm was performed. Follow-up angiography showed complete occlusion of the aneurysm. The patient suffered from severe headaches which were no longer present 6 months after treatment.

CONCLUSIONS

The WEB intraaneurysmal flow diverter can be effectively used as combined support and embolization device for the treatment of complex aneurysms in selective cases where other catheterization and embolization strategies have failed.

Simmons Angled microguidewire INsertion to the Target (SAINT) technique in neuroendovascular therapy

Advancing appropriate microcatheters is essential for treatment. However, we still encounter inaccessible arterial branches because of the anatomical arrangement. While many successful techniques regarding microcatheters have been reported, there have been very few reports of microguidewire-shaping techniques. We developed the Simmons-Angled microguidewire INsertion to the Target (SAINT) technique for insertion of the microguidewire into inaccessible arterial branches. The SAINT technique is feasible for selection and insertion into arteries that are inaccessible with conventional methods.

The Role of Transcatheter Arterial Embolization in the Management of Nonvariceal Upper Gastrointestinal Bleeding

Nearly 50 years ago, catheter angiography was introduced as a means of both diagnosing and treating nonvariceal upper gastrointestinal bleeding. Technological advances and innovations have resulted in the introduction of microcatheters that, using a coaxial technique, are capable of selecting third-order arterial branches and of delivering a wide array of embolic agents. This article reviews the imaging diagnosis of nonvariceal upper gastrointestinal bleeding, the techniques of diagnostic and therapeutic angiography, the angiographic appearance of the various etiologies of nonvariceal upper gastrointestinal bleeding, the rationale behind case-specific selection of embolic agents as well as the anticipated outcome of transcatheter arterial embolization.

Transcatheter arterial embolization for upper gastrointestinal tract bleeding

Introduction

Transcatheter arterial embolization is a possible treatment for patients with recurrent bleeding from the upper gastrointestinal tract after failed endoscopic management and is also an alternative to surgical treatment.

Aim

To analyze the outcomes of transcatheter arterial embolization and identify the clinical and technical factors that influenced the rates of morbidity and mortality.

Material and methods

A retrospective analysis was carried out, based on the data of 36 patients who underwent transcatheter arterial embolization for acute nonvariceal upper gastrointestinal bleeding in 2013 to 2015 in our center. An analysis was performed between early rebleeding rates, mortality and the following factors: patient sex, age, number of units of packed red blood cells and packed plasma administered to the patients, length of hospital stay, therapeutic or prophylactic embolization.

Results

The technical success rate of the embolization procedure was 100%. There were 15 (41.70%) therapeutic embolizations and 21 (58.3%) prophylactic embolizations. There was a 77.8% clinical success rate. Following embolization, 10 (27.80%) patients had repeated bleeding and 9 (25.0%) patients died. Significant associations were found between rebleeding and prophylactic embolization (OR = 10.53; p = 0.04) and between mortality and prophylactic embolization (OR = 10.53; p = 0.04) and units of packed red blood cells (OR = 1.25; p < 0.01).

Conclusions

In our experience, transcatheter arterial embolization is a safe treatment method for acute nonvariceal upper gastrointestinal bleeding and a possible alternative to surgery for high-risk patients.