title: Development of thrombus in the major systemic and portal veins after balloon-occluded retrograde transvenous obliteration for treating gastric variceal bleeding: its frequency and outcome evaluation with CT.
abstract: OBJECTIVE
  To investigate the frequency and outcome of the thrombus that developed in the major systemic and portal veins after balloon-occluded retrograde transvenous obliteration (BRTO) by comparing the computed tomographic (CT) scans obtained before and after BRTO treatment.
  
  
  METHODS
  Sixty patients with liver cirrhosis who underwent BRTO to treat gastric variceal bleeding were included in this study. The pre- and postprocedural CT scans in these patients were retrospectively compared to evaluate thrombus development in the major systemic and portal veins after BRTO. Thrombus was classified as having a high attenuation (ie, containing iodized oil), combined attenuation, or low attenuation. The outcome of the thrombus that developed in those veins after BRTO was evaluated by reviewing the serial follow-up CT scans.
  
  
  RESULTS
  After BRTO, 14 thrombi developed in 13 systemic and portal veins of nine of the 60 patients (15%). Eleven of the 14 thrombi had high attenuation, two thrombi had low attenuation, and one thrombus had a combined attenuation. The 13 affected veins included six splenic veins, four left renal veins, and three main portal veins. On the serial follow-up CT scans (range of the follow-up period, 5-25 months), all 11 high-attenuation thrombi were completely resolved without sequelae in the affected veins. One of the two low-attenuation thrombi disappeared with severe slitlike collapse of the affected left renal vein; the other low-attenuation thrombus had progressed and it caused complete occlusion of the affected main portal vein. One thrombus with a combined attenuation was almost completely resolved without sequelae in the affected splenic vein, despite the transient enlargement of the low-attenuation component.
  
  
  CONCLUSIONS
  In this study, the frequency of thrombus development in the major systemic and portal veins after BRTO was 15%. Although iodized oil deposited in those veins appears to be of no great importance, the low-attenuation thrombus can be associated with occlusion of the affected vein. These tendencies, however, require validation in a larger series.
authors: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Ilwon-dong 50, Kangnam-gu, Seoul 135-710, Korea.
authors: Sung Ki
authors: SK
authors: Cho
authors: Sung Wook
authors: SW
authors: Shin
authors: Young Soo
authors: YS
authors: Do
authors: Kwang Bo
authors: KB
authors: Park
authors: Sung Wook
authors: SW
authors: Choo
authors: Sam Soo
authors: SS
authors: Kim
authors: In Wook
authors: IW
authors: Choo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021721:Balloon Occlusion / Q000009:adverse effects*; D004932:Esophageal and Gastric Varices / Q000000981:diagnostic imaging / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011169:Portal Vein; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology*