Ryoji Iwamoto

Follow-up of true visceral artery aneurysm after coil embolization by three-dimensional contrast-enhanced MR angiography.

PURPOSE We aimed to evaluate the outcomes of coil embolization of true visceral artery aneurysms by three-dimensional contrast-enhanced magnetic resonance (MR) angiography. MATERIALS AND METHODS We used three-dimensional contrast-enhanced MR angiography, which included source images, to evaluate 23 patients (mean age, 60 years; range, 28-83 years) with true visceral artery aneurysms (splenic, n=15; hepatic, n=2; gastroduodenal, n=2; celiac, n=2; pancreaticoduodenal, n=1; gastroepiploic, n=1) who underwent coil embolization. Angiographic aneurysmal occlusion was revealed in all cases. Follow-up MR angiography was conducted with either a 1.5 or 3 Tesla system 3-25 months (mean, 18 months) after embolization. MR angiography was evaluated for aneurysmal occlusion, hemodynamic status, and complications. RESULTS Complete aneurysmal occlusion was determined in 22 patients (96%) on follow-up MR angiography (mean follow-up period, 18 months). Neck recanalization, which was observed at nine and 20 months after embolization, was confirmed in one of eight patients (13%) using a neck preservation technique. In this patient, a small neck recanalization covered by a coil mass was demonstrated. The complete hemodynamic status after embolization was determined in 21 patients (91%); the visualization of several collateral vessels, such as short gastric arteries, after parent artery occlusion was poor compared with that seen on digital subtraction angiography in the remaining two patients (9%). An asymptomatic localized splenic infarction was confirmed in one patient (4%). CONCLUSION Our study presents the follow-up results from three-dimensional contrast-enhanced MR angiography, which confirmed neck recanalization, the approximate hemodynamic status, and complications. This effective and less invasive method may be suitable for serial follow-up after coil embolization of true visceral aneurysms.

Detection of Neck Recanalization with Follow-up Contrast-enhanced MR Angiography after Renal Artery Aneurysm Coil Embolization

embryologic development, there is a metameric disposition of the arteries of the trunk. These trunk arteries provide blood supply to the parietal wall (ie, posterior arteries), to the urogenital tract (ie, lateral arteries) and to the intestinal tract (ie, anterior arteries). During evolution, regression of several of these ventral, metameric arteries is observed, as well as the regression of the ventral anastomoses of these metameric arteries. This embryonic development eventually results in the formation of three residual anterior arteries at the 10th, 13th, and 21st or 22nd root, respectively, corresponding to celiac, superior mesenteric, and inferior mesenteric arterial anatomy as seen in the adult vasculature. However, in some cases the mechanism of regression of metameric arteries and of their ventral anastomoses can be distorted, resulting in different anatomic variants. In the present case, it can be hypothesized that the proximal anastomosis between the root, which later formed the superior and inferior mesenteric artery, persisted and progressively developed at the level of the initial 21st or 22nd root, the normal origin of the inferior mesenteric artery. Additionally, persistence of another root, located at the level of the 12th to 14th root, could have resulted in the presence of an accessory branch, originating from the aorta at the level of the first lumbar vertebra and supplying a part of the ileum. Finally, it is clear that the knowledge of variant or aberrant vascular anatomy is of importance so as not to overlook a potential source of gastrointestinal hemorrhage during visceral angiography.

Ultraselective arterial embolization of vasa recta using 1.7-French microcatheter with small-sized detachable coils in acute colonic hemorrhage after failed endoscopic treatment.

OBJECTIVE The purpose of this article is to document our experiences with ultraselective arterial embolization to manage acute colonic hemorrhage using a 1.7-French microcatheter with small-sized detachable coils and to discuss the feasibility and clinical efficacy of this new technique. CONCLUSION We achieved technical success in all four patients with the sole use of short-segment embolization of the long branch of the vasa recta. Our findings suggest that this technique is useful for embolization in cases of colonic hemorrhage.

A newly developed double lumen microballoon catheter with a side hole: initial experience of intraarterial infusion chemotherapy and/or embolization

PurposeTo introduce a newly developed double lumen microballoon catheter with a side hole for intraarterial infusion chemotherapy and/or embolization.Methods and materialsSeven patients with malignant tumors, for whom superselective catheterization was considered difficult or had failed, underwent intraarterial infusion chemotherapy and/or embolization with the 3.3-Fr microballoon catheter. The catheter has a double lumen and a side hole to facilitate infusion from the proximal end of the balloon. The balloon was placed on the distal side of the target artery branching site. Inflation of the balloon and occlusion of the main lumen with the tip of the occlusion device allowed for intraarterial infusion chemotherapy and/or embolization of the target artery via the side hole.ResultsSuccessful intraarterial infusion chemotherapy and/or embolization with the microballoon catheter was performed in all patients with no complications.ConclusionsThe newly developed microballoon catheter achieves intraarterial infusion chemotherapy and/or embolization without the need for superselective catheterization.

Pelvic arteriovenous malformation treated by superselective transcatheter venous and arterial embolization

We describe a rare case of hematuria and hemospermia associated with pelvic arteriovenous malformation (AVM) in a male patient treated by transcatheter embolization. Understanding AVM hemodynamics contributes to the elucidation of its pathology and improves the outcome of embolization. In the present case, multiple arteriolar components shunted to the initial part of a single dominant outflow vein. Superselective embolization of a draining vein and feeding artery with an n-butyl cyanoacrylate/lipiodol mixture and polyvinyl alcohol particles was effective in terms of shunt disappearance and minimizing the need for subsequent arterial embolization.

Ultraselective embolization using a 1.7-Fr catheter and soft bare coil for small intestinal bleeding.

Abstract Objective: We aimed to evaluate the safety and efficacy of embolization using a 1.7-Fr catheter and soft bare coil to treat acute small intestinal bleeding. Material and methods: Subjects were five consecutive patients who experienced onset of melena with small intestinal bleeding and underwent transcatheter arterial embolization with 1.7-Fr catheters and 0.010-inch detachable bare coils (five procedures in total). Technical success, clinical success, relative post-procedural complications, arterial bleeding source and cause, and relationship between coagulopathy and embolization efficacy were examined by capsule endoscopy. Results: We achieved 100% technical and clinical success for the five transcatheter arterial embolizations. All catheterizations of the vasa recta of the bleeding artery (jejunal artery, n = 2; ileal artery, n = 3) were possible with a 1.7-Fr catheter. We achieved high embolization efficacy in two patients with coagulopathy. No rebleeding, intestinal ischemia, or necrosis was observed on follow-up capsule endoscopy. We confirmed that peptic ulcers/ulcer scars were the cause of bleeding for all patients. Conclusion: Embolization with 0.010-inch coils using a 1.7-Fr catheter and catheterization of the vasa recta of bleeding vessels was effective and safe for treating small intestinal bleeding.

Management of visceral artery embolization using 0.010-inch detachable microcoils.

Transcatheter coil embolization is used primarily to treat arterial hemorrhages, tumors, aneurysms, and vascular malformations. However, conventional microcatheter systems cannot always be employed in difficult cases. In this technical note, we describe how small-diameter primary coils and microcatheter tips that are thinner than normal can be used to increase the safety and reliability of coil embolization.

Dietary small bowel obstruction

A 59-year-old man with no history of abdominal or intestinal surgery, trauma or psychiatric illness presented to our hospital with abdominal pain and vomiting. Physical examination revealed hyperactive bowel sounds and lower abdominal tenderness. Abdominal CT revealed a small bowel obstruction in the lower abdominal space, possibly due to obstruction of the fusiform low attenuation (–162 Hounsfield units) region (figure 1, arrows), and suspected ileal stricture on the anal side of the low-attenuation region. The region was similar …