Page 7 - Clinical Connections- Summer 2021

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