Page 2 - Clinical Connections - Summer 2022

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vascular malformation; and concluded a Brockman said: “Because of the history of
CT scan would be an invaluable additional trauma and the high probability that Lorna
investigation. had an acquired traumatic kink in her caudal
Lorna had CT of her thorax and abdomen vena cava that was responsible for the post-
on returning to the hospital in May. At that sinusoidal venous hypertension, we elected
point the combined cardiology and surgery to explore the cava through a right sixth
teams were able to confirm that Lorna intercostal thoracotomy. At surgery, the scar
had an extremely rare malformation of her tissue responsible for the ‘kink’ was very
caudal vena cava, resulting in high pressure obvious and incorporated the right phrenic Lorna's surgery was led by Professor Dan
in her caudal vena cava (Budd-Chiari nerve, which was discontinuous. Brockman, Director of the Cardiothoracic
Surgery Programme
like syndrome), that was the cause of her “Having released the cava from the scar
ascites. Her heart was found to be otherwise tissue, the caudal caval pressure remained Recovery and progress
normal in structure. slightly above cranial caval pressure, so Lorna recovered from surgery uneventfully
Lorna’s clinical presentation was a patch of pericardium was sutured into a and was discharged on antiplatelet drugs
comparable to other dogs reported in the longitudinal incision across the stricture, (aspirin and clopidogrel) for one month,
veterinary literature describing kinking and made in the caudal cava made inside a to reduce the risk of clots forming on the
tortuosity of the caudal vena cava. Previously carefully positioned Satinsky clamp. This pericardial patch. The owners were asked
documented dogs often presented in young reduced the caudal caval pressure such to go to the referring practice for staple
adulthood following blunt thoracic trauma. that it was just above mean cranial caval removal and then return to the RVC for
Lorna's history of a possible altercation pressure.” check-up.
with a deer, and imaging evidence of rib She returned for her check-up towards
fractures, mirrored these cases. the end of August, prior to which she
Possible treatments included surgical had been doing very well at home. On
exploration and resection of the scar tissue examination she was bright, alert and
causing obstruction, resection of the narrow responsive. Her mucous membranes were
part of the caudal cava and catheter-guided pink and moist with a capillary refill time
balloon dilation of the lesion with stent of under two seconds. Her heart rate was
placement. No one on the RVC team had 92, with synchronous pulses. Her thoracic
performed treatment on such a lesion but auscultation and abdominal palpation were
we suspected that balloon dilation and/or unremarkable, with no evidence of a fluid
stenting would be a less appropriate option thrill. Doppler echocardiography revealed
as the kinking of the vena cava was likely a structurally normal heart, as before.
associated with fibrous tissue causing there was no evidence of congestion of the
extra-luminal compression and there would abdominal aorta or hepatic veins and no
be a high risk of recurrence of the stricture ascites so strong evidence that caudal caval
and we preferred to avoid an intravascular hypertension had been relieved. Lorna went
implant in such a young dog. on to come 4th in her category at Crufts.
Lorna’s owners decided to go ahead with Lorna's surgery for an acquired obstruction to
surgery, and she returned for admission on her caudal vena cava
July 6th. Outlining the process, Professor

CT angiogram reconstruction of kinked vena cava

For small animal referrals, please call:
01707 666399
Email:
qmhreception@rvc.ac.uk

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2 Summer 2022