Page 8 - Clinical Connections - Summer 2024

RVC RESEARCH STUDY VETERINARY SERVICES RVC.AC.UK
Hypophysectomy
PITUITARY SURGERY AND CLINICAL
RESEARCH AT THE RVC

Joe Fenn, Senior Lecturer in Veterinary Neurology and Neurosurgery, and Chris Scudder, Senior
Lecturer in Small Animal Internal Medicine
ince performing the UK’s first
successful feline hypophysectomy
S surgery, in April 2012, to treat
a cat with hypersomatotropism and
diabetes mellitus, the team at the RVC
has been following the progress of such
patients closely, allowing them to conduct
groundbreaking clinical research into
pituitary diseases in cats and dogs.
Some of the team’s research findings
have already helped to pave the way
for more widely available and effective
treatments for pituitary diseases in cats and
dogs, with further exciting projects ongoing.
Transsphenoidal hypophysectomy
(surgical removal of the pituitary gland at the Coat changes in a dog before (left) and after (right) transsphenoidal hypophysectomy
base of the brain, via the roof of the mouth)
requires a team of skilled neurosurgeons, our understanding the pathological several areas for further investigation,
critical care, internal medicine and mechanisms that underpin pituitary with studies underway aiming to improve
anaesthesia specialists. Consequently, it is tumours. Our team have identified outcomes further and learn more about their
not widely available in veterinary medicine. described the histopathological changes management.
The procedure is most often performed seen in the pituitary glands of cats with The RVC team have also been active
at RVC Small Animal Referrals to treat cats hypersomatotropism, reported the gene in pioneering research into the use of
with pituitary tumours causing acromegaly expression of these tumours and identified transsphenoidal hypophysectomy in
and diabetes mellitus and dogs with tumours some interesting correlations between gene dogs. In 2022, RVC neurosurgeon Joe
causing pituitary-dependent Cushing’s expression and tumour characteristics. Fenn contributed to a multicentre study
syndrome. In 2021, the team published a description developing a novel 3D-printed patient-
After obtaining consent from the owners of their findings in the first 68 cats with specific surgical drill guide for the use in
of pets who had undergone pituitary surgery acromegaly and diabetes mellitus treated performing hypophysectomy in dogs, where
at the RVC, clinical records and residual by transsphenoidal hypophysectomy. It the patient anatomy can be more variable
pituitary tissue samples (which remained was the largest such study that has been and challenging.
after diagnostic tissue analysis) have been reported. This study was able to show that The team also published the
utilised in several clinical research projects cats with acromegaly and diabetes mellitus first description of transsphenoidal
in recent years. treated surgically are very likely to have hypophysectomy for the treatment of
their acromegaly cured and their diabetic acromegaly in a dog, in 2023. This
Advancements in understanding and control improved, with 71% of diabetic cats publication was able to show for the first time
treatment requiring no further insulin after surgery. that dogs can demonstrate resolution of the
These studies have hugely advanced our This research has played a key role soft tissue and hair coat changes seen with
understanding of these pituitary diseases, in the development of transsphenoidal acromegaly, following surgical removal of
as well as our ability to offer more effective hypophysectomy as a widely accepted the causative pituitary tumour.
treatments to owners from across the treatment choice for cats with acromegaly In addition to these examples of published
country and further afield. and diabetes mellitus. The findings in research, there are several exciting ongoing
Initial research focused on further these first 68 cats have also provided projects at the RVC investigating aspects
of pituitary surgery, including long-term
patient quality of life, postoperative blood
parameter changes, changes in oxytocin (a
hormone produced by the posterior lobe of
the pituitary gland) production, and the role
of MRI in the diagnosis of pituitary tumours
before surgery.

For small animal referrals, please call:
01707 666399
A normal pituitary (left) and a case with acromegaly (right). Both samples underwent Email:
immunohistochemistry for growth hormone, with growth hormone positive cells stained brown qmhreception@rvc.ac.uk

8 Summer 2024