title: Depiction of variants of the portal confluence venous system using multidetector row CT: analysis of 916 cases.
abstract: OBJECTIVE
  Detailed knowledge of the venous mesenteric system is important for gastrointestinal surgery, particularly for transplantation planning and surgery and for the comprehension of perioperative complications that may influence patient outcome. Data about the mesenteric venous anatomy in the literature varies substantially. The purpose of this study was to categorize venous mesenteric variants and to determine their incidence.
  
  
  METHODS
  We included 916 patients requiring diagnostic abdominal CT in the portal venous phase. The mesenteric vein anatomy was categorized as follows: 1. the inferior mesenteric vein (IMV) enters the splenic vein (SV); 2. the IMV enters into the angle of the confluence of the SV and superior mesenteric vein (SMV) forming the portal vein (PV); 3. the IMV enters the SMV; 4. seven rare variants. We measured the diameters of the veins and distances from the confluence to the IMV origins.
  
  
  RESULTS
  The frequency of variants was: 1. 37.6%, 2. 28.8%; 3. 19.2%. The rare variants totaled 14.4%. The average vessel diameters measured in cm: PV 1.48; SV 1.02; SMV 1.2; IMV 0.5. The mean IMV entering distances were 1.66 cm in variant 1 and 0.75 cm in variant 3.
  
  
  CONCLUSIONS
  The three common variants (1, 2 and 3) are the most relevant ones. 14.4% of patients had different anatomic variants. The variability of the mesenteric venous system was higher than previously published. Knowledge of rare variants is important to avoid complications in abdominal surgery.
authors: Abteilung für Diagnostische und Interventionelle Radiologie, Universitätsklinikum Tübingen, Germany. patrickkrumm@gmail.com
authors: P
authors: P
authors: Krumm
authors: C
authors: C
authors: Schraml
authors: C
authors: C
authors: Bretschneider
authors: A
authors: A
authors: Seeger
authors: B
authors: B
authors: Klumpp
authors: U
authors: U
authors: Kramer
authors: C D
authors: CD
authors: Claussen
authors: S
authors: S
authors: Miller
mesh_terms: D000005:Abdomen / Q000098:blood supply / Q000601:surgery; D000008:Abdominal Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007431:Intraoperative Complications / Q000000981:diagnostic imaging / Q000517:prevention & control; D007472:Iohexol / Q000031:analogs & derivatives; D008297:Male; D008642:Mesenteric Veins / Q000000981:diagnostic imaging*; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D010690:Phlebography / Q000379:methods*; D010865:Pilot Projects; D011169:Portal Vein / Q000002:abnormalities / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013162:Splenic Vein / Q000002:abnormalities / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide