title: Feasibility of power contrast injections and bolus triggering during CT scans in oncologic patients with totally implantable venous access ports of the forearm.
abstract: BACKGROUND
  Conventional totally implantable venous access ports (TIVAPs) are not approved for power contrast injections but often remain the only venous access site in oncologic patients. Therefore, these devices can play an important role if patients with a TIVAP are scheduled for a contrast-enhanced computed tomography (ceCT) as vascular access may become more difficult during the course of chemotherapy.
  
  
  OBJECTIVE
  To evaluate the feasibility and safety of power injections in conventional TIVAPs in the forearm and to analyze the feasibility of bolus triggering during CT scans.
  
  
  METHODS
  In this retrospective study we analyzed 177 power injections in 141 patients with TIVAPs in the forearm. Between October 2008 and March 2010 all patients underwent power injections (1.5 mL/s, 150 psi) via the TIVAP for ceCT because conventional vascular access via a peripheral vein had failed. Adequate functioning and catheter's tip location after injection were evaluated. Peak injection pressure and attenuation levels of aorta, liver and spleen were analyzed and compared with results of 50 patients who were injected via classical peripheral cannulas (3 mL/s, 300 psi). Feasibility of automatic scan initiation was evaluated. In vitro the port was stressed with 5 mL/s (300 psi).
  
  
  RESULTS
  One TIVAP showed tip dislocation with catheter rupture. Three (2.1%) devices were explanted owing to assumed infection within 4 weeks after the injection. Mean injection pressure was 121.9 +/-24.1 psi. Triggering with automatic scan initiation succeeded in 13/44 (29.6%) scans. Injection via classical cannulas resulted in significantly higher enhancement (p < 0.05). In vitro the port system tolerated flow rates of up to 5 mL/s, injection pressures of up to 338 psi.
  
  
  CONCLUSIONS
  Power injection is a safe alternative for patients with TIVAPs in the forearm if classic vascular access ultimately fails. Triggering was successful in one-third of the attempts. Image quality in the arterial phase scan may be hampered. In vitro results suggest that the device tolerates even higher flow rates.
authors.affiliation: Julius-Maximilians-University of Würzburg, Institute of Radiology, Oberdürrbacher Str. 6, 97080 Würzburg, Germany. Goltz@roentgen.uni-wuerzburg.de
authors.forename: Jan Peter
authors.initials: JP
authors.lastname: Goltz
authors.forename: Wolfram
authors.initials: W
authors.lastname: Machann
authors.forename: Claudia
authors.initials: C
authors.lastname: Noack
authors.forename: Dietbert
authors.initials: D
authors.lastname: Hahn
authors.forename: Ralph
authors.initials: R
authors.lastname: Kickuth
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002405:Catheterization, Central Venous; D002408:Catheters, Indwelling; D003287:Contrast Media / Q000008:administration & dosage*; D005240:Feasibility Studies; D005260:Female; D005542:Forearm; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging*; D015642:Radiology, Interventional / Q000379:methods; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media