title: Sonographic assessment of spleen stiffness before and after transjugular intrahepatic portosystemic shunt placement with or without concurrent embolization of portal systemic collateral veins in patients with cirrhosis and portal hypertension: a feasibility study.
abstract: OBJECTIVE
  To determine the feasibility of spleen stiffness measurement in the evaluation of portal hemodynamics in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) placement.
  
  
  METHODS
  We prospectively correlated the spleen stiffness as measured by the shear wave velocity with the portal pressure and portosystemic gradient in patients undergoing TIPS procedures. Twenty-three consecutive patients referred for placement of a TIPS were enrolled. Included in our study were 19 patients in whom a spleen stiffness measurement was obtained before, immediately after, and 1 to 3 days after placement. Spleen stiffness was measured by calculating the Young modulus estimated from the shear wave velocity. A 2-tailed nonparametric Mann-Whitney U test was used to assess statistically significant differences in spleen stiffness measurement after TIPS placement, and regression analysis was used to correlate spleen stiffness measurement with portal pressure.
  
  
  RESULTS
  After TIPS placement, the spleen stiffness measurement increased, with a mean increase in the Young modulus ± SD of 6.54 ± 6.29 kPa in 42% of patients (8 of 19). In the remaining 58% (11 of 19), the spleens became softer after TIPS placement (Young modulus decreased by 9.57 ± 8.82 kPa). Eight patients, including 5 with concurrent embolization or thrombosis of competitive shunts, had increased spleen stiffness. The mean change in the median spleen stiffness before and after TIPS placement between the patients with and without competitive shunts was statistically significantly different (P < .04, nonparametric Mann-Whitney U test). There was no measurable correlation between spleen stiffness measurement and portal pressure before and after TIPS placement.
  
  
  CONCLUSIONS
  This study demonstrates the feasibility of a noninvasive spleen stiffness measurement, which could complement conventional sonography with additional functional information in patients undergoing TIPS procedures.
authors.affiliation: Department of Radiology, Divisions of Vascular and Interventional Radiology (P.M.N., K.C.) and Abdominal Imaging (J.M.R.), University of Michigan Health System, Ann Arbor, Michigan USA. paulanov@umich.edu.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Novelli
authors.affiliation: Department of Radiology, Divisions of Vascular and Interventional Radiology (P.M.N., K.C.) and Abdominal Imaging (J.M.R.), University of Michigan Health System, Ann Arbor, Michigan USA.
authors.forename: Kyung
authors.initials: K
authors.lastname: Cho
authors.affiliation: Department of Radiology, Divisions of Vascular and Interventional Radiology (P.M.N., K.C.) and Abdominal Imaging (J.M.R.), University of Michigan Health System, Ann Arbor, Michigan USA.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Rubin
mesh_terms: D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy / Q000379:methods; D003937:Diagnosis, Differential; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D004621:Embolization, Therapeutic / Q000379:methods*; D005355:Fibrosis / Q000150:complications / Q000628:therapy*; D006801:Humans; D006975:Hypertension, Portal / Q000150:complications / Q000628:therapy*; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging; D019168:Portasystemic Shunt, Transjugular Intrahepatic / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013154:Spleen / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: gastrointestinal ultrasound; portal hemodynamics; portal hypertension; sonography; spleen stiffness; transjugular intrahepatic portosystemic shunt; variceal bleeding