Page 5 - Clinical Connections - Summer 2022
P. 5

Advancements

     TEN YEARS OF HYPOPHYSECTOMY AT THE
     RVC


     Joe Fenn, Senior Lecturer in Veterinary Neurology and Neurosurgery
     T    he  UK’s  first  successful  feline   decade ago, commented: "I am immensely   advantage over radiation therapy. Medical
                                                                              management of cats with acromegaly and
                                    was
                                          proud of my team at the RVC and the
          hypophysectomy
                           surgery
          performed  at  the  RVC  in April  2012,
                                                                              and can be extremely challenging for owners
                                          extremely gratifying, not only in seeing the
     to treat a cat with acromegaly and diabetes   programme we have set up. It has been   diabetes mellitus is typically cost prohibitive
     mellitus. Since then, the RVC team has   marked benefits to our patients and their   to maintain effectively.
     treated 120 cats and 25 dogs with pituitary   families, but also to know we have been at
     tumours, providing treatment for pets and   the forefront of a paradigm shift in how these
     owners for which there have traditionally   common and debilitating conditions are
     been limited options.                treated in our pets."
      Over the past decade, collaboration   Over the six years since Patrick left the
     between skilled neurosurgeons, critical   RVC, we have developed a great deal
     care, internal medicine and anaesthesia   of experience with the technique and
     specialists has enabled RVC Small Animal   have seen a range of challenging cases.
     Referrals to deliver hypophysectomy   Hypophysectomy is most frequently
     treatment regularly and remain a global   performed at the RVC in patients suffering
     leader in this area.                 from acromegaly and pituitary-dependent
                                          Cushing’s syndrome, caused by hormone-
                                          producing pituitary tumours.

                                          Acromegaly and diabetes mellitus in cats  Rusty, an acromegaly patient treated in 2019
                                          Although it is a technically challenging,
                                          surgical hypophysectomy is now considered   The team at the RVC has also recently
                                          the optimal treatment option for feline   successfully performed hypophysectomy for
                                          acromegaly. Over the past 10 years of   the first time to treat a rare case of a dog with
                                          performing the procedure, the team at the   acromegaly, marking another landmark in
                                          RVC have placed great emphasis on using   the use of this procedure in pets.
                                          their experience to maximise patient safety
      Hypophysectomy surgery              and outcome, with the mortality rate falling   Pituitary-dependent Cushing’s syndrome
                                          from around 15% initially to 6% for the past   Hypophysectomy is also an excellent
      Transsphenoidal hypophysectomy      50 cats treated.                    treatment option for pituitary-dependent
     involves the removal of a tumour affecting   In cats with acromegaly and diabetes   Cushing’s syndrome, most often seen in
     the pituitary gland from the base of the   mellitus, hypophysectomy is associated   dogs with pituitary tumours. Dogs typically
     brain through the soft palate in the mouth.   with a 70% rate of surviving cats achieving   recover very quickly post-operatively and are
     Access to this area of the brain is technically   complete diabetic remission post-operatively,   often discharged within five days. Resolution
     difficult and the team at the RVC is helped by   with significant improvements in insulin   of the clinical signs of Cushing’s is typically
     cutting-edge diagnostic imaging and surgical   responsiveness seen in the vast majority of   dramatic and dogs demonstrate an excellent
     equipment, such as the Brainsight neuro-  the other 30% of patients. Cats typically stay   quality of life post-operatively. Although
     navigation system head frame.        at the Queen Mother Hospital for Animals for   less frequently encountered, the team has
      This approach was pioneered at the RVC   a week to 10 days post-operatively while the   also treated a handful of cats with pituitary-
     in 2012 by Neurology and Neurosurgery   team stabilises their diabetes mellitus.   dependent Cushing’s syndrome.
     specialist, Patrick Kenny, who when   Hypophysectomy only involves one     Although other options are available for
     reflecting on this achievement starting a   general anaesthetic procedure, providing an   treatment of pituitary dependent Cushing’s
                                                                              syndrome, including life-long trilostane
                                                                              therapy and radiotherapy, hypophysectomy
                                                                              confers advantages over these options,
                                                                              including the removal of the growing tumour
                                                                              and potential for complete cessation of
                                                                              hormone production. Whilst radiation therapy
                                                                              results in a reduction of tumour size and
                                                                              associated neurological signs, improvements
                                                                              in hormone production remain very variable.

                                                                                      For small animal referrals, please call:
                                                                                     01707 666399
                                                                                      Email:
      Pituitary dependent Cushings syndrome caused by a tumour was resolved by hypophysectomy   qmhreception@rvc.ac.uk


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