Jpn J Intervent Radiol Vol.22 No.1 2007

State of the Art
Clinics in Venous Thromboembolism

1. Mechanism of Blood Coagulation and Anticoagulation
Department of Laboratory Medicine, Tokyo Medical University
Morio Arai

 Latest review of blood coagulation is based on cells having tissue factor and/or negativelycharged phospholipids on the surface. When vessel damage occurs, circulating factor VIIa makes a complex with tissue factor which appears on the endothelial cells or subendothelium.
Factor VIIa/tissue factor complex then activates factors IX to produce factor IXa. Factor IXa subsequently activates factor X in the presence of factor VIIIa. Factor Xa activates prothrombin in the presence of factor Va to produce thrombin. These three steps of tetramer formation contribute to the catalytic efficiency in over 20 orders of magnitude resulting in a thrombin burst at the site of injury. Anticoagulation system also proceeds in the locus of cell surface with ligands of heparin sulfate proteoglycans and thrombomodulin.

Key words
● Coagulation
● Anticoagulation
● PT

2. Epidemiology and Pathophysiology of Venous Thromboembolism
Department of Cardiology, Mie University Graduate School of Medicine
Norikazu Yamada

 Deep vein thrombosis and pulmonary thromboembolism (PTE) represent a continuum of one disease entity (venous thromboembolism (VTE)). Although the incidence of VTE has been increasing in Japan recently, the diffusion of primary prevention for VTE is expected to reduce the incidence of VTE. Acute cor pulmonale and hxpoxemia are the main pathophysiological effects in acute PTE. Both the magnitude of thromboemboli and pre-existing cardiopulmonary reser ve are responsible for the hemodynamic consequences. The treatment option is recommended to be chosen according to the clinical severity of acute PTE.

Key words
● Pulmonary thromboembolism
● Deep vein thrombosis
● Epidemiology
● Pathophysiology

3. Diagnostic Strategy for VTE
Department of Radiology, Shiga University of Medical Science
Masashi Takahashi, Akira Furukawa, Norihisa Nitta, Michio Yamasaski, Ryutaro Takazakura, Toyohiko Tanaka, Yukihiro Nagatani, Kiyoshi Murata

 An optimal diagnostic approach for the VTE has been discussed over several decades. By introducing modern technologies in recent years, such as D-dimer and MDCT, the diagnostic strategy has been markedly changed. In this article, the authors have attempted to summarize the method, accuracy and pitfalls of each diagnostic test first. Second, the proposed diagnostic flow-chart for the VTE was discussed. Finally, the techniques, interpretation and pitfalls of the CTPA were described.

Key words
● VTE(venous thromboembolism)
● PE(pulmonary embolism)
● Diagnosis

4. Drug Treatment of Venous Thromboembolism
Medical Education Center, School of Medicine Keio University
Toru Satoh

 This review is written based on the evidence-based guidelines for venous thromboembolism announced at the 7th ACCP (American College of Chest Physicians) conference on antithrombotic and thrombolytic therapy, and summarized in an article on Chest in 2004. As the treatment of acute pulmonary embolism has much in common with that of deep vein thrombosis, the latter topic is mainly described and necessary information only on pulmonary embolism is added. As acute drug therapy, antithrombotic drugs such as unfractionated heparin and low molecular heparin are the mainstay of therapy. The pharmaceutical characteristics, indications, administration period and methods, dosage determination and side effects of these drugs are discussed. Thrombolytic drugs such as urokinase, streptokinase and tPA should only be used in patients with shock with paticular concern about bleeding complications. As maintenance therapy, coumadin antithrombotic drug is administered for a period determined by the cause of the disease to prevent recurrence and reduce mortality. The usage of coumadin antithrombotic drug is also summarized.

Key words
● Drug treatment
● Deep vein thrombosis
● Acute pulmonary embolism
● Venous thromboembolism

5. Treatment for Deep Venous Thrombosis with Interventional Radiological Procedures
Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine
Takuji Yamagami, Takeharu Kato, Tatsuya Hirota, Rika Yoshimatsu, Tomohiro Matsumoto, Tsunehiko Nishimura

 The initial symptoms of deep venous thrombosis (DVT) in the lower extremities may be quite severe, and, additionally, there is substantial risk of pulmonary embolism. Moreover, in DVTs that remain delayed complications are possible, including the spectrum of debilitating symptoms referred to as post-thrombotic syndrome. Therefore, treatment of DVT is necessary.
 Even when systemic anticoagulation or thrombolytic therapies for deep venous thrombosis are ineffective, the addition of interventional radiological procedures such as catheter directed thrombolysis often is effective in the disappearance of DVT. Acceptance of usage of tissueplasminogen activator variants might be desirable to make therapies more effective.
 Prophylactic use of inferior vena cava filters during treatment of deep venous thrombolysis is controversial. However, in our daily clinical work, we have experienced many situations in which if a filter had not been implanted during interventional radiological procedures of DVT, severe pulmonary embolism might have occurred. When such prophylactic use of filters is required, retrievable vena cava filter might be advantageous.

Key words
● Deep venous thrombosis
● Interventional Radiology
● Vena cava filter

6. Catheter Intervention and Surgery for Acute Pulmonary Thromboembolism
Cardiovascular Surgery, National Cardiovascular Center
Hitoshi Ogino

 Acute pulmonar y thromboembolism is a lethal event associated with deep shock or cardiopulmonary arrest. For this disorder, the first choice of emergency treatment is anticoagulant or anti-thrombolytic therapy. However, in critical cases with deep shock or cardiac arrest due to massive pulmonar y thromboembolism, emergency catheter inter vention or surgical treatment is mandator y. In addition, some patients with acute pulmonar y thromboembolism develop chronic type with pulmonar y hyper tension, for which only surgical treatment is indicated. In this article, catheter intervention and surgical treatment for pulmonary thromboembolism are described.

Key words
● Pulmonary thromboembolism
● Catheter intervention(IVR)
● Surgical treatment

7. Prevention of Venous Thromboembolis
Department of Cardiology, Mie University Graduate School of Medicine
Mashio Nakamura

 Venous thromboembolism (VTE) has been a common illness even in Japan and gets increased social as well as medical attention, especially in inpatients. However, we can not use western guidelines in Japan, because the incidence of VTE might be lower, available medicines are different such as low molecular weight heparin and anti-Xa agents, and public awareness of VTE is still lower in Japan. Therefore, Japanese guidelines are necessary. Although we have little Japanese evidence about prevention of VTE, we completed creation of Japanes guidelines together with 10 medical societies. The guidelines are based on ACCP guideline which employs a 4 risk category style. We assumed that the incidence of VTE in Japanese was one level lower than that in western people. We used the coverage medicine only, and gave priority to mechanical prevention because we wanted to avoid bleeding complications. Our future tasks are diffusion of these guidelines, reevaluation of the guidelines after using them, and evidence collection of Japanese VTE. At this time, it is important that we develop the effort of VTE prophylaxis based on the Japanese guidelines in each hospital.

Key words
● Anticoagulation
● Deep vein thrombosis
● Pulmonary thromboembolism

Original Article
Transcatheter Arterial Embolization for Pancreaticoduodenal Artery Pseudoaneurysm in Patients with Variant Arterial Anatomy : The Value of Oblique View as a Vascular Road Map
Department of Radiology, Internal Medicine1) and Surgery2), Saiseikai Fukuoka General Hospital
Madoka Yamauchi, Shunichi Matsumoto, Makiko Koike
Tetsuo Watanabe, Teppei Kabemura1), Hiroshi Matsuura2)

Purpose : To evaluate the technical and clinical outcomes of transcatheter arterial embolization (TAE) for arterial bleeding from the pancreaticoduodenal region in patients with variant arterial anatomy.
Methods : The study group consisted of four patients who had undergone TAE for arterial bleeding from the pancreaticoduodenal region, including pancreatitis (n=2), pancreatic tumor (n=1), and duodenal ulcer (n=1). The clinical records and angiographic findings were retrospectively reviewed.
Results : TAE was successfully performed in all of the four patients. In two patients, the initial selective angiographies from the superior mesenteric and celiac arteries could not identify the source of bleeding. For these two patients, additional oblique views and superselective angiography were useful. There were no serious complications or recurrent bleeding during the follow-up period of 2 weeks to 27 weeks (mean 12 weeks).
Conclusion : TAE is a safe and effective non-surgical treatment of choice for arterial bleeding from the pancreaticoduodenal region. Because of the complexity of the arterial anatomy of the pancreaticoduodenal region and intermittent nature of the bleeding, additional oblique views and superselective angiography may be helpful in detecting the source of the bleeding.

Key words
● Transcatheter arterial embolization (TAE)
● Pseudoaneurysm
● Pancreaticoduodenal region

Original Article
Blunt Splenic Injury : Procedure of Appropriate Assessment of Degree of Injury and Technique of Embolotherapy
Department of Radiology, Shiga University of Medical Science
Naoaki Kono, Akira Furukawa, Michio Yamasaki, Toyohiko Tanaka, Norihisa Nitta, Keizo Bun, Akinaga Sonoda, Masashi Takahashi, Kiyoshi Murata
Department of Radiology, Koseikai Takeda Hospital
Shuzo Kanasaki
Department of Radiology, Ijinkai Takeda Hospital
Kohichi Kawakami
Department of Radiology, Kusatsu General Hospital
Kiyosumi Maeda
Department of Radiology, Saiseikai Noe Hospital
Yasuo Ohnaka
Department of Radiology, Kohka Public Hospital
Katsuji Imoto, Tsutomu Sakamoto

Purpose : To assess the role of contrast-enhanced CT in patients with blunt splenic injury and to evaluate technique of transcatheter arterial embolization.
Material/Methods : Twenty-six patients with blunt splenic injury were retrospectively reviewed ; 1) degree of injury, 2) therapy applied and 3) patient outcome. Regarding patients who received angiography, findings on CE-CT and angiograms were compared. Technique of embolotherapy used was recorded.
Results : Initial treatment was conservative in 11, embolotherapy in 11, and surgery in 4. Most patients with capsular and subcapsular injury were treated conservatively, while patients with deep parenchymal injury, particularly with a large amount of abdominal bleeding, often required embolotherapy or surgery. Compared to angiography, CT was more sensitive in demonstrating parenchymal injury. In most cases, embolotherapy was performed super selectively for all injured arterial branches with metallic coils. Embolization was usually performed for all branches supplying injured segments on CT, in addition to actively bleeding arteries on angiogram. Treatment was successful in all but 3 cases. In one case who received embolotherapy and re-bleed, embolization was performed only for arteries with active bleeding on angiogram.
Conclusions : CE-CT is helpful in making the appropriate choice of treatment. Super selective embolotherapy seemed to be successful when the injured arterial branches are precisely assessed with angiography and CE-CT.

Key words
● Splenic injury
● Transcatheter arterial

Case Report
Endovascular Treatment of Postpartum Deep Venous Thrombosis : A Case Report
Department of Radiology, Shimane University Faculty of Medicine
Shingo Koyama, Jun Yoshigi, Naruhito Okada, Tomonori Nakamura, Takeshi Yoshizako, Nobue Uchida, Hajime Kitagaki
Department of Radiology, Hyogo Medical Center for Adults
Kenta Izaki

Gestational and postpartum periods are known as high risk conditions for deep venous thrombosis (DVT). Many authors have reported that endovascular treatments such as direct infusion of thrombolytic agent, removal of thrombus and angioplasty are safe and effective management methods for DVT.
We report a case of postpartum DVT successfully treated with endovascular therapy.
A 30-year-old woman noticed swelling and pain in her left lower leg after childbirth.
Pulmonary embolism and thrombus between the left common iliac vein and popliteal vein were recognized on enhanced CT. Systemic thrombolysis was ineffective, and so endovascular treatment was undertaken. We first placed a temporary IVC filter, and then performed catheter-directed thrombolysis of urokinase via a 4-French catheter placed into the occluded left femoral vein approaching from the left popliteal vein. After
shrinking the thrombus, we performed balloon angioplasty. Disappearance of the DVT and improvement of venous blood flow was noted 10 days after completion of treatment. The patient shows no recurrence 14 months later.
Endovascular treatment reduced long-term post-thrombotic morbidity and improved quality of life, especially for a young puerperant patient like in this case.

Key words
● Deep vein thrombosis
● Catheter-directed thrombolysis
● Postpartum

Technical Note
Application of Coaxial Micro-balloon Catheter (Attendant) for Treatment of Hepatocellular Carcinoma
Department of Radiology, National Hospital Organization Nagasaki Medical Center
Hideki Ishimaru, Keiko Ishimaru, Kazunori Mitarai, Takeshi Koshiishi, Yohjiro Matsuoka, Akiko Egawa, Toshifumi Fujimoto
Department of Radiology Science,Nagasaki University Graduate School of Biomedical Sciences
Tomonori Murakami, Ichiro Sakamoto, Masataka Uetani

To be effective and to avoid major complications when performing transcatheter arterial infusion chemotherapy(TAI)or transcatheter arterial chemoembolization(TACE)in the treatment of hepatocellular carcinoma(HCC), super-selective catheterization has been necessary. However, when super-selective catheterization is not technically possible, hemodynamic alteration using a balloon catheter is another procedure that can be used to obtain ideal drug delivery for TAI and TACE. "Attendant" is a commercially available, coaxial-type, micro-balloon catheter with which infusion via a guide wire lumen is possible while its balloon is inflated. We report on our experience in the use of this balloon catheter for the treatment of HCC in 11 patients(15 sessions). This unique balloon catheter is useful when hemodynamic alteration is needed for performing TAI and TACE.

Key words
●Micro-balloon catheter
●Transcatheter therapy
●Hepatocellular carcinoma