Jpn J Intervent Radiol Vol.28 No.1 2013

State of the Art
Fundamentals of Interventional Neuroradiology

An Introduction  
Ichiro Ikushima
Department of Radiology, Miyakonojo Regional Medical Center

1. Cerebral Aneurysm

Department of Neuroendovascular Therapy, Kohnan Hospital
Ichiro Suzuki, Ryushi Kondo, Yasushi Matsumoto

The frequency of endovascular treatment for cerebral aneurysms has increased recently with rapid improvements in the devices. It is the basic technique of the intraaneurysmal coil embolization that coiling is performed with a single microcatheter and more coil placemnet with controlling the microcatheter and the selection of suitable coils. Although rapid technological advances in the endovascular field have revolutionized the treatment of cerebral aneurysms, it is important to understand and acquire the basic techniques. We will review the literatures and findings of recent coil embolization for cerebral aneurysms and highlight the importance of the basic technique. The following will also be explained: parent artery occlusion with coils for large or giant aneurysms, technical procedure of balloon test occlusion, procedure-related complications of intraaneurysmal coil embolization, how to deal with the complications and troubles during coil embolization, stent assisted coil embolization as a newer technical method, and bioactive coils as a newer coil.

Key words

  • Endovascular treatment
  • Cerebral aneurysm
  • Coil embolization

2. Endovascular Recanalization Therapy for Acute Ischemic Stroke

Department of Neurosurgery and Radiology1), Miyakonojo Regional Medical Center
Hajime Ohta, Ichiro Ikushima1)

The treatment of acute ischemic stroke has evolved during the past 10 years. The use of intravenous recombinant tissue plasminogen activator (rt-PA) is the gold standard therapy for acute ischemic stroke within 4.5-hours from symptom onset. However, there are some limitations and problems associated with use of this drug. Endovascular recanalization therapy is administrered as an option for patients with contraindications for intravenous rt-PA therapy. Pharmacological recanalization therapy, such as intraarterial injection of a thrombolytic agent, has demonstrated benefit for acute MCA occlusion within 6 hours from onset. Combination of IV and IA thrombolysis may be successful when each single strategy failed. Endovascular mechanical thrombectomy with Merci retriever and Penumbra system shows great potential in acute stroke treatments. Recently, stent-like clot retrieval devices achieved substantially better angiographic, safety, and clinical outcomes than did the Merci Retrieval system. In this article, we will review current treatment options for acute ischemic stroke, focusing on the latest advances in the fields of mechanical recanalization.

Key words

  • Acute ischemic stroke
  • Mechanical thrombectomy
  • Stent-like device

3. Carotid Artery Stenting: A Review Article

Department of Neurosurgery, Kokura Memorial Hospital
Ryota Ishibashi, Tsuyoshi Ohta, Ichiro Nakahara

Stenosis of extracranial carotid arteries is one of the leading causes of ischemic stroke. There are three options for the treatment of carotid artery stenosis: best medical treatment (BMT), carotid endarterectomy (CEA) and carotid artery stenting (CAS). Recently, CAS has been developed as an alternative to CEA with a number of clinical trials performed to compare CEA with CAS. A number of criteria, such as degree of stenosis, plaque characteristics, symptoms, age, anatomical conditions and combined diseases must be taken into account in considering the strategy of CAS for the individual patient. In Japan, precise preoperative assessment of the CAS risks such as vulnerability of plaque, cerebral hyperperfusion, and cardiovascular adverse events has reduced perioperative morbi-mortality. This article gives a brief overview and comment on the current treatment strategies of extracranial carotid artery stenosis based on the recent literature and our experiences.

Key words

  • Carotid artery stenting
  • Carotid endarterectomy
  • Carotid stenosis

4. Role of Endovascular Treatment for Arteriovenous Malformations

Neurosurgery, Kobe City Medical Center General Hospital and KCGH Stroke Center
Tatsuya Ishikawa, Yohei Mineharu, Hirotoshi Imamura, Nobuyuki Sakai

Embolization of arteriovenous malformations (AVMs) is commonly used to achieve nidal volume reduction before surgical extirpation and stereotactic radiosurgery. Two commonly used liquid embolics are N-butyl cyanoacrylate (NBCA) and OnyxTM. OnyxTM is a nonadhesive agent with longer polymerization time leading to better penetration of the nidus compared with NBCA. In our department, 20 patients with AVMs were treated with OnyxTM. 16 patients underwent a surgical resection, and 3 underwent radiosurgical treatment. Angiographically, more than 75% obliteration was achieved in 16 patients (80%). Procedure-related permanent neurological deficits were observed in 3 patients. OnyxTM embolization is a safe and effective treatment for AVMs.

Key words

  • Arteriovenous malformation (AVM)
  • Embolization
  • Onyx

5. Embolizaton of the Dural Arteriovenous Fistulas

Department of Radiology, Oita University Hospital
Hiro Kiyosue

Symptoms of dural arteriovenous fistulas (AVFs) vary from asymptomatic-mild symptoms to fatal hemorrhage. The best treatment should be selected among several treatment options, including open surgery, interventional techniques, stereotactic radiation therapy, and conservative management, based on the condition of the patient, risks of aggravating symptoms, and risks related to each technique. Although the majority of cases with dural arteriovenous fistulas can be treated by interventional techniques including transarterial embolization and transvenous embolization, application of interventional techniques has to be selected based on the angioarchitecture and hemodynamic features of the dural AVFs and venous drainage from normal neural tissue. Non-sinusal dural AVFs/spinal dural AVFs are highly associated with aggressive symptoms, and should be completely occluded by open surgery or transarterial embolization with liquid embolic materials. Selection of the two techniques depends on the location of the fistula (deep or superficial) and presence of dangerous feeding arteries. Transvenous embolization should be considered as a first-line option for the treatment of sinusal dural AVFs/spinal epidural AVFs. Selective transvenous embolization of the shunted venous pouch has been recently applied for the treatment of sinusal dural AVFs. It can selectively occlude the fistulous pouches of dural AVF with preservation of the sinus lumen for cases with dural AVF with antegrade sinus flow. Sinus packing should be performed for cases in which the affected sinus does not serve as a route of cerebral venous drainage. Careful attention should be paid to small retrograde cerebral venous drainage of dural AVFs during sinus packing because residual retrograde drainage to a small cerebral vein can cause fatal hemorrhage or venous infraction during or after sinus packing. Pretherapeutic evaluation of the drainage veins of dural AVFs, cerebral venous drainage, location of the fistulas, shunted venous pouches, and feeding arteries is essential to achieve a safe and successful procedure.

Key words

  • Acute ischemic stroke
  • Mechanical thrombectomy
  • Stent-Like device

Case Reports

Fatal Hepatic Gas Gangrene due to Clostridium Perfringens Infection after Transcatheter Arterial Chemoembolization

Department of Radiology and Gastroenterological Medicine1), Shinko Hospital
Yoshiaki Watanabe, Shuichi Monzawa, Nami Yuasa
Akihiro Higashida1), Hajime Yamada1)
Department of Community Medicine and Social Healthcare Science,
Division of Legal Medicine, Kobe University Graduate School of Medicine
Takeshi Kondo

We report a case that died of septicemia complicated with massive hemolysis subsequent to hepatic gas gangrene due to Clostridium perfringens infection after transcatheter arterial chemoembolization (TACE) for hepatocellular carcinomas (HCCs).
A man in his 60s who had been treated for several HCCs with radiofreqency ablation and TACE previously underwent TACE for newly diagnosed HCCs. He had a past history of multiple myeloma and bladder cancer. His clinical status and blood test data were unremarkable after TACE. He was discharged 4 days after TACE uneventfully. He complained of fever and abdominal pain 7 days after TACE. The next day, he was admitted to our hospital. CT scans demonstrated a large abscess with prominent gas collection in the liver, and blood test data indicated severe septicemia with massive hemolysis. He died 3 hours after admission. Bacterial blood culture test detected Clostridium perfringens, and autopsy revealed gas gangrene in the liver.
Although Clostridium perfringens infection is expected to occur rarely after TACE, it may cause a fatal gas gangrene in the liver and is one of the complications that interventionists should keep in mind.

Key words

  • Transcatheter arterial chemoembolization
  • Clostridium perfringens
  • Gas gangrene
  • Hepatocellular carcinoma
  • Liver

Case Reports

Cystic Artery Bleeding due to Blunt Gallbladder Injury Treated with Transcatheteral Arterial Embolization

Department of Radiology and Surgery1), Kohka Public Hospital
Akitoshi Inoue, Kunio Hamanaka, Kentaro Itabashi, Katsuji Imoto
Michio Yamasaki, Tsutomu Sakamoto, Munechika Tsuji1)
Department of Radiology, Tokyo Metropolitan University
Akira Furukawa

A woman in her 60s with cystic arterial hemorrhage after blunt abdominal trauma, successfully treated by transcatheter arterial embolization (TAE) is reported. She was transferred to the emergency department and underwent ultrasonography and contrast-enhanced CT, which revealed hematoma and contrast extravasation at the gallbladder bed. Emergent angiography was performed immediately and extravasation from the posterior branch of the cystic artery was confirmed. Micro-catheter was then introduced to the bleeding arterial branch carefully and TAE was performed with several pieces of gelatin sponge (2mm), which stopped the hemorrhage. A follow-up CT showed no complications such as cystitis or gallbladder necrosis, and the patient was discharged uneventfully 18 days after the admission.

Key words

  • Transcatheter arterial embolization(TAE)
  • Blunt gallbladder injury
  • Cystic artery

Case Reports

A Case of Ruptured Traumatic Hepatic Artery Pseudoaneurysm into the Biliary Tract Cured by Transcatheter Arterial Embolization after Episodes of Gastrointestinal Bleeding

Department of Emergency and Critical Care Medicine and Radiology1),
Yokohama City Minato Red Cross Hospital
Tetsuya Takahashi, Toshitaka Ito, Hideho Endo1), Michiko Fujisawa
Ryo Hiromi, Tetsuhiro Takei, Keiichi Yagi

A man in his 40s, injured when he fell off a roller coaster, underwent emergent hepatorrhaphy and gauze packing for a large crush injury of the right hepatic lobe with extravasation and intraabdominal bleeding. The postoperative course was uneventful, but black stool was observed on day 21; upper gastrointestinal tract endoscopy revealed no abnormality, including in the papilla of Vater. A trend towards improvement of bloody stool was observed; therefore, conservative treatment was continued. However, as large amounts of black stool and severe right hypochondriac pain occurred on day 25, abdominal dynamic CT was performed, which revealed a round tumorous shadow of uniform density about 20 mm in diameter, with a clear boundary, in the damaged region of the anterior segment of the right hepatic lobe, suspected to be caused by a ruptured hepatic artery pseudoaneurysm into the biliary tract. Angiography revealed that the A5/A8 branching region of the right hepatic artery anterior segment branch fed into the aneurysm, and gelatin sponge injection and parent artery coil embolization of A8, A5 and the right hepatic artery anterior segment branch were performed, which led to effectively controlled the bleeding. Thus, the possibility of ruptured hepatic artery pseudoaneurysm must be considered in cases of gastrointestinal bleeding after hepatic injuries, and a system should be established for transcatheter arterial embolization (TAE) to be performed quickly when necessary.

Key words

  • Hepatic pseudoaneurysm
  • Hemobilia
  • Gastrointestinal bleeding

Technical Note

Efficacy of Ultrasonography with Multimodality Fusion Imaging for Percutaneous Puncture and Drainage of Intra-abdominal Abscess

Department of Internal Medicine, Hokkaido Gastroenterology Hospital
Takuro Machida, Shoichi Horita

'Multimodality fusion imaging’is a recently developed system that synchronizes CT, MRI, or US images with real-time US images.
This method was applied to attempts at percutaneous drainage for 14 patients with intra-abdominal abscesses, which were difficult to visualize by US, instead of using CT guidance.
We safely accomplished drainage and decreased exposure to radiation in all cases.
Herein, we introduce a technique for therapeutic drainage of intra-abdominal abscesses using this multimodality fusion imaging system.

Key words

  • Multimodality fusion imaging
  • Drainage
  • Intra-abdominal abscess