Page 8 - Clinical Connections - Summer 2024
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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
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