title: Clinical features and natural history of portal vein thrombosis after radiofrequency ablation for hepatocellular carcinoma in Japan.
abstract: OBJECTIVE
  Little is known about portal vein thrombosis (PVT) after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). We aimed to determine the incidence, background, and natural history of RFA-related PVT.
  
  
  METHODS
  This is a retrospective study of 317 patients (219 males and 98 females) with HCC treated by RFA. Clinical data were compared between patients with and without PVT detected by ultrasound/CT. The median follow-up period after RFA was 15.8 months.
  
  
  RESULTS
  PVT was detected in 6 (1.9 %) of 317 patients, 6 (0.8 %) of 802 treatments for HCC, and 6 (0.6 %) of 964 sessions of RFA. Body mass index was significantly higher in patients with PVT (26.9 ± 3.1 kg/m(2)) than in those without (22.9 ± 3.5 kg/m(2), p = 0.0075). PVT was significantly more frequent in RFA for the left lobe of the liver (2.7 %) than for the other sites (0 %, p < 0.0001). Five of the six patients received no treatment for PVT, with natural outcomes of disappearance in one patient, improvement in one patient, and unchanged appearance in three patients. Anticoagulation was applied in the one remaining patient and resulted in a successful recanalization. In the six patients, there was no significant difference in hepatic functional reserve between baseline and time of detection of PVT.
  
  
  CONCLUSIONS
  These results indicated that a high body mass index and RFA for HCC in the left lobe might be significant risk factors for PVT and that RFA-related PVT was rarely progressive with little influence on liver function.
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. bobtaro51@yahoo.co.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Shimada
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. maru-cib@umin.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maruyama
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. takakondonaika@yahoo.co.jp.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. tad_sekimoto@yahoo.co.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sekimoto
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. machat1215@yahoo.co.jp.
authors.forename: Masanori
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. tenyu0614@gmail.com.
authors.forename: Tenyu
authors.initials: T
authors.lastname: Motoyama
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. s-oga@cf7.so-net.ne.jp.
authors.forename: Sadahisa
authors.initials: S
authors.lastname: Ogasawara
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. eiichiro0709@hotmail.com.
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Suzuki
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. ooyh@hotmail.com.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Ooka
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. akinobutawada@hospital.chiba-u.jp.
authors.forename: Akinobu
authors.initials: A
authors.lastname: Tawada
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. techiba@faculty.chiba-u.jp.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Chiba
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. fumikanai@gmail.com.
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Kanai
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. okabeshin1966@yahoo.co.jp.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Okabe
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. yoshikawa@faculty.chiba-u.jp.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Yoshikawa
authors.affiliation: Department of Gastroenterology, Chiba University Graduate School of Medicine, 1-8-1, Inohana, Chuou-ku, Chiba, 260-8670, Japan. yokosukao@faculty.chiba-u.jp.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yokosuka
keywords: Hepatocellular carcinoma; Portal vein thrombosis; Radiofrequency ablation