Page 7 - Clinical Connections- Summer 2021
P. 7

Figure 2: This figure shows the schematic (A), CT angiography (B) and volume rendered (C) images of a dog with a subdivision of a central divisional
         intrahepatic shunt, inserting via the quadrate hepatic vein. The quadrate hepatic vein courses in its normal position to the left of the gallbladder (on the
         right side of the images) but is markedly dilated due to the increased blood flow through this vessel.
        images had been previously published.   subtle differences between shunt types
        Also, variations to the pre-existing   could be identified. The team noticed that   ABBREVIATIONS FOR
                                                                                 IMAGES
        classification system, which was originally   the vast majority of the shunts that they
        based upon ultrasonographic imaging,   encountered inserted into the intrahepatic   PV   portal vein
        were often encountered in the clinic at the   caudal vena cava at the expected position   RPB  right portal branch
        RVC.                                of a normal systemic hepatic vein, a   LPB   left portal branch
                                            finding that had not previously been
        International Collaboration         reported. This concept of complex shunt   CVC  caudal vena cava
        The RVC team, led by Associate Professor   morphology being based upon the existing   LHV  left hepatic vein
        in Diagnostic Imaging Randi Drees   normal anatomy is similar to that recently   CHV  central hepatic vein
        and Diagnostic Imaging Resident Mark   described for extrahepatic portosystemic   DRM  dorsal right medial hepatic vein
        Plested, began investigating the topic in   shunts.                      RL   right lateral hepatic vein
        2018. They collaborated with three other   Classically, intrahepatic portosystemic   Ca   caudate hepatic vein
        referral centres in the USA – the University   shunts have been divided into right, left and
        of California, Davis, the University of   central divisional types. This study showed   VRM  ventral right medial hepatic vein
        Tennessee, and the University of Georgia.   that within these groups, various subtypes   Qu   quadrate lobar vein
        In total, more than 90 dogs with a diagnosis   are possible depending on the hepatic   GB   gallbladder
        of an intrahepatic portosystemic shunt   vein through which the shunt inserts.
        were included in a retrospective descriptive   For example, amongst right divisional   had multiple sites of shunt insertion.
        study.                              shunts, the majority insert via the right   When writing the paper, the RVC
          Each of the dogs had a diagnosis of an   lateral hepatic vein, while a small subset   team was keen that the diagrams and
        intrahepatic portosystemic shunt, based on   insert via the caudate hepatic vein. This   figures included should be able to tell the
        a CT angiography study of the abdomen.   distinction can help determine if surgical   whole story independently of the text.
        Each of the CT studies were reassessed   attenuation of the abnormality is possible,   The complex 3D anatomy of the various
        by the RVC team. The studies were   and optimally plan for an efficient surgical   shunt types were simplified using various
        assessed multiple times, comparing the   approach in these challenging cases. The   schematic diagrams, and were presented
        abnormal livers to the normal anatomy,   study has also opened up a new avenue   alongside multiplanar reconstructions of
        and gradually grouping together patients   of research that could lead to further   the CT images of each of the shunt types.
        with similar shunt morphologies. By   investigations on the subject, particularly in   The team was assisted by a professional
        having a large sample of dogs to assess,   the documentation that nearly 10% of dogs   medical illustrator, Chrisoula Toupadakis
                                                                                Skouritakis, to produce clear and concise
         AMERICAN COLLEGE OF VETERINARY RADIOLOGY (ACVR)                        images that could be used for reference
         RESIDENT AUTHOR AWARD
                                                                                when assessing clinical cases.
         This year, the study mentioned in the article was awarded the American College   Following publication of the study in
         of Veterinary Radiology (ACVR) Resident Author Award by Veterinary Radiology &   the Veterinary Radiology & Ultrasound
         Ultrasound, an annual award that recognises high quality resident-authored papers.  journal in 2020, the novel classification
         The judges commented that this impressive descriptive study provided novel   system has been used throughout the
         information for a common condition, with excellent figures and lots of attention to detail.   QMHA by both the radiology and surgery
         The paper demonstrated the benefit of inter-institutional research with a clear clinical   teams. Its introduction has improved both
         benefit.                                                               the consistency of radiological reporting
         On receiving the award, the article lead author Mark Plested said: “We are so glad this   and the clarity of communication between
         paper was well received, we already see it is helping radiologists on the clinical floor   clinicians regarding these complex cases.
         every day to more precisely diagnose this disease in our canine patients and aids the
         surgical team in decision making and treatment planning.”
         Randi Drees, who supervised the study, said: “I am so proud of Mark, his attention to     For small animal referrals, please call:
         anatomical detail and superb analytic and writing skills have made this complex topic   01707 666399
         easily accessible to the veterinary community and will help dogs every day.”    Email:
                                                                                     qmhreception@rvc.ac.uk
                                                                                                    Summer 2021   7
   2   3   4   5   6   7   8   9   10   11