Assessment of intraoperative mesenteric portovenography in cogenital portosystemic shunt surgery

Macdonald, Nicholas James (2002) Assessment of intraoperative mesenteric portovenography in cogenital portosystemic shunt surgery. MVM(R) thesis, University of Glasgow.

Abstract

The aim of this study was to assess the hepatic portal vasculature visible on an intraoperative mesenteric portovenogram. The portovenograms of 100 animals were independently assessed by two experienced observers. Two scoring systems were developed, a subjective visual analogue scale and a novel objective scoring system. These two systems were assessed for repeatability, reproducibility and interchangeability. The portovenograms studied consisted of an initial portovenogram, prior to manipulation of the portosystemic shunt, and a second portovenogram following temporary full occlusion of the shunting vessel. The hepatic portal vasculature was compared between the pre-occlusion and post-occlusion portovenograms. These findings were used to investigate the relationship between portal atresia / hypoplasia and the pre-occlusion portovenograms. The surgical records of the 100 animals were examined and the portovenograms of those animals which underwent only partial ligation of their portosystemic shunt were compared with those which tolerated full ligation. There was no statistical difference between the two observers when scoring the same portovenogram for either the visual analogue scale (P = 0.730, reproducibility coefficient = 17.85 units) or the objective scoring system (scores identical, reproducibility coefficient = 0). There was no statistical difference, for either of the observers, when the same portovenogram was assessed on two separate occasions using the visual analogue scale (observer 1, P = 0,-35, repeatability coefficient = 17.93 units; observer 2, P = 0.42, repeatability coefficient = 8.27 units) or the objective scoring system (scores given by both observers were identical, repeatability coefficient = 0 for both observers). The results of comparison between the visual analogue scale and objective scoring system confirmed that the two scoring systems were not directly interchangeable. Although both scoring systems demonstrated good reproducibility and repeatability, the objective scoring system possessed a number of inherent deficiencies that suggested it was not the method of choice for the assessment of the subjective data obtained from intraoperative mesenteric portovenography. The pre-occlusion scores were significantly different to the post-occlusion scores using both scoring systems (P<0.01 for both). Animals with apparent portal atresia / hypoplasia on pre-occlusion portovenography were found to have a wide range of scores on post-occlusion portovenograms, as high as 98 units using the visual analogue scale and 13 on the objective scoring system. The full ligation group had significantly higher portovenogram scores than the partial ligation group both pre- and post-occlusion, using either scoring system (P<0.01 for all tests).

• Item Type: Thesis (MVM(R))
• Qualification Level: Masters
• Additional Information: Adviser: Carolyn Burton
• Keywords: Veterinary medicine, surgery.
• Subjects: S Agriculture > SF Animal culture > SF600 Veterinary Medicine
• Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Supervisor's Name: Supervisor, not known
• Date of Award: 2002
• Depositing User: Enlighten Team
• Unique ID: glathesis:2002-71383
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 10 May 2019 10:49
• Last Modified: 18 May 2021 10:54
• URI: https://theses.gla.ac.uk/id/eprint/71383