title: Comparison of the spread of two different volumes of contrast medium when performing ultrasound-guided transversus abdominis plane injection in dog cadavers.
abstract: OBJECTIVE
  To compare, via CT imaging, the spread of different volumes of diluted iodinated contrast medium in the transversus abdominis muscle plane of dog cadavers.
  
  
  METHODS
  Prospective, randomised study. An electro stimulation or a SonoTAP needle was inserted in plane with the ultrasound beam in the fascia between the internal oblique and transversus abdominis muscles. A test dose of 1 ml of diluted contrast (30 mg/mL iohexol) was injected to confirm positioning, followed by 0 · 5 mL/kg (n=14) or 1 mL/kg (n=12) and the distribution of the fluid compared.
  
  
  RESULTS
  Contrast medium was identified exclusively in the transversus abdominis plane in 19 of 26 dogs. In one dog, the contrast lay between the external and internal oblique muscles and partially in three dogs. Intraperitoneal contrast was detected in 6 of 26 dogs (23%). No significant differences were found in the dorso-ventral or cranio-caudal spread or area of distribution but a significant difference was found in the transverse spread. There was an association between poor ultrasound visualisation of the tip of the needle and intraperitoneal injection.
  
  
  CONCLUSIONS
  Injection of 1 mL/kg of diluted contrast did not result in wider cranio-caudal spread in the transversus abdominis muscle plane of dog cadavers when compared with 0 · 5 mL/kg. Intraperitoneal injection is a risk and might be reduced with good needle visualisation.
authors.affiliation: School of Veterinary Science, University of Liverpool, CH64 7TE, Neston, UK.
authors.forename: A
authors.initials: A
authors.lastname: Zoff
authors.affiliation: Prof. Agregado F. Veterinaria y Ciencias Experimentales, Universidad Católica de Valencia "San Vicente Mártir", Valencia, 46001, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Laborda-Vidal
authors.affiliation: School of Veterinary Science, University of Liverpool, CH64 7TE, Neston, UK.
authors.forename: J
authors.initials: J
authors.lastname: Mortier
authors.affiliation: Lumbry Park Veterinary Specialists, GU34 3HF, Alton, UK.
authors.forename: M
authors.initials: M
authors.lastname: Amengual
authors.affiliation: School of Veterinary Science, University of Liverpool, CH64 7TE, Neston, UK.
authors.forename: E
authors.initials: E
authors.lastname: Rioja
mesh_terms: D034861:Abdominal Wall / Q000294:innervation*; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000493:pharmacokinetics; D000818:Animals; D002102:Cadaver; D004396:Coloring Agents / Q000008:administration & dosage; D004285:Dogs / Q000378:metabolism*; D009407:Nerve Block / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D011446:Prospective Studies; D014463:Ultrasonography / Q000662:veterinary*
chemical_list: D000779:Anesthetics, Local; D004396:Coloring Agents