title: Influential factors and formation of extrahepatic collateral artery in unresectable hepatocellular carcinoma.
abstract: OBJECTIVE
  To analyze the influence factors and formation of extrahepatic collateral arteries (ECAs) in unresectable hepatocellular carcinoma (HCC) with or without chemoembolization.
  
  
  METHODS
  Detailed histories of 35 patients with 39 ECAs of HCC and images including computerized tomography scan, digital subtraction angiography were reviewed carefully to identify ECAs of HCC, ECAs arising from, and anatomic location of tumors in liver. Tumor sizes were measured, and relations of ECAs with times of chemoembolization, tumor size, and the anatomic tumor location were analyzed. Complications were observed after chemoembolization through ECAs of HCC with different techniques.
  
  
  RESULTS
  Influence factors of formation of ECAs of HCC included the times of repeated chemoembolization, the location of tumors in liver, the tumor size and the types of chemoembolization. ECAs in HCC appeared after 3-4 times of chemoembolization (17.9%), but a higher frequency of ECAs occurred after 5-6 times of chemoembolization (56.4%). ECAs presented easily in peripheral areas (71.8%) of liver abutting to the anterior, posterior abdominal walls, the top right of diaphragm and right kidney. ECAs also occurred easily after complete obstruction of the trunk arteries supplying HCCs or the branches of proper hepatic arteries. Extrahepatic collaterals of HCC originated from right internal thoracic (mammary) artery (RITA, 5.1%), right intercostal artery (RICA, 7.7%), left gastric artery (LGA, 12.8%), right inferior phrenic artery (RIPA, 38.5%), omental artery (OTA, 2.6%), superior mesenteric artery (SMA, 23.1%), and right adrenal and renal capsule artery (RARCA, 10.3%), respectively. The complications after chemoembolization attributed to no super selective catheterization.
  
  
  CONCLUSIONS
  The formation of ECAs in unresectable HCC is obviously correlated with multiple chemoembolization, tumor size, types of chemoembolization, anatomic location of tumors. Extrahepatic collaterals in HCC are corresponding to the tumor locations in liver.
authors.affiliation: Department of Diagnostic and Interventional Radiology, The Affiliated Sixth People's Hospital of Shanghai Jiaotong University, 600 Yi Shan Rd, Shanghai 200233, China. wylzxy@tom.com
authors.forename: Yong-Li
authors.initials: YL
authors.lastname: Wang
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Li
authors.forename: Ying-Sheng
authors.initials: YS
authors.lastname: Cheng
authors.forename: Hai-Bing
authors.initials: HB
authors.lastname: Shi
authors.forename: Hai-Lun
authors.initials: HL
authors.lastname: Fan
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000453:epidemiology / Q000628:therapy*; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D015994:Incidence; D008102:Liver Circulation / Q000502:physiology; D008113:Liver Neoplasms / Q000098:blood supply* / Q000453:epidemiology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000628:therapy; D011859:Radiography