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 Visit  to  the  Department  of  Pediatric  Cardiovascular  Anesthesiology,    

Texas  Children’s  Hospital,  USA    

Dr  Alyson  Walker,  MBChB  BSc  MRCP  FRCA  Consultant  Paediatric  Anaesthetist,  Royal  Hospital  for  Sick  Children,  Glasgow,  Scotland  

 June  2014  

Funded  by  a  travel  fellowship  from  the  Madeleine  Steele  Fund      

     Texas   Children’s   Hospital   (TCH)   has   one   of   the   largest   congenital   cardiac   surgery  programmes  in  the  world.    They  performed  almost  800  cardiac  operations  in  2012  and  predict   that   this  number  may  be   closer   to  1000  by   the  end  of   this  year.  TCH  recently  moved   into   second  place   in   the  US  News  Best  Children’s  Hospitals   for   this  Cardiology  and  Cardiac  Surgery  department.    During  my  visit  to  TCH  I  gained  a  rich  experience  of  past,  present  and  future  practices.    I  am  very  grateful  to  the  Madeleine  Steele  Fund  for  the  opportunity  to  have  visited  this  institution.            Operating  room    TCH   have   three   busy   cardiac   theatres   and   three  cardiac   catheterisation   laboratories.   I   saw   a   variety  of  clinical  cases  including:  Tetralogy  of  Fallot  repair,  atrioventricular   septal  defect   repair,   arterial   switch,  lung   transplant,   heart   harvest   and   transplant,  Heartmate   ®   ventricular   assist   device   insertion  among   others.     During   these   cases,   I   had   the  opportunity   to   observe   and   discuss   the   chosen  anaesthetic   techniques  with   the  anaesthetic   team.     I  also   had   some   fascinating   discussions   with   the  perfusionists   who   explained   the   rationale   behind  their   perfusion   strategies   which   vary   slightly   from  those  I  have  experienced  to  date.            

Cardiopulmonary  Bypass  at  TCH  

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Paediatric  Cardiac  Anaesthesia,  the  TCH  way    Although  there  are  many  similarities  in  anaesthetic  practice  between  our  institution  and  TCH,   there  are  several  differences.  Examples  of  such  differences   include  Aprotinin  not  being  available  in  the  USA  and  their  use  of  ε-­‐amonicaproic  acid  and  recombinant  factor  VII  (NovoSeven®).    The   TCH   cardiac   anaesthesia   department   has  expertise   in   the   field   of   neuroprotection   during  cardiac   surgery   and   have   published   widely   on   the  subject.  Bilateral  NIRS  monitoring  is  used  for  all  cases.    We   also   use   this   technique   in   the   Royal   Hospital   for  Sick  Children  in  Glasgow  and  so  further  experience  in  its   interpretation   and,   in   particular,   resultant   actions  was  useful.    Dexmedetomidine   is   used   at   TCH   for   peri-­‐operative  sedation-­‐   a   drug   I   have   not   yet   used   in   clinical  practice.    This  drug  is  gaining  interest  in  the  paediatric  anaesthetic  community  because  of   the   possibility   that   it   may   lead   to   less   neuroapoptosis   and   so   lead   to   improved  neurological  outcomes   following  cardiac  surgery.    This   theory  has  yet   to  be  proven   in  the   clinical   setting.     TCH   is   currently   researching   the   pharmacokinetics   and   safety  profile  of  dexmedetomidine  in  paediatric  cardiac  surgery.   I  observed  its  use  in  theatre  and  intensive  care  and  will  be  interested  to  read  the  results  of  this  study  when  they  are  published.      Educational  &  Organisational  Meetings    There   is   an   environment   of   continuing   education   within   the  department   and   many   meetings   to   attend.     Dean   Andropolous   and  Emad  Mossad  are  editors  of  one  of  the  main  textbooks  on  anaesthesia  for   congenital   cardiac   surgery   (1).     During   my   visit,   I   attended   the  cardiac  conference,  grand  rounds  on  the  subjects  of  Tetralogy  of  Fallot  and   Transposition   of   the   Great   Arteries   and   departmental   clinical  discussions.      

 Cardiovascular  Intensive  Care  Unit    Situated  next  to  the  OR  suite,  the  CVICU  has  21  beds.    I  joined  the  ward  round  on  several  occasions   overseeing   the   great   variety   of   cardiac   patients   at   TCH.     I  met   children   on  ventricular  assist  devices  (e.g.  Berlin  EXCOR  Heart  ®).  The  only  centres  in  the  UK  who  fit   these   for   children   are   the   Freman  Hospital   in  Newcastle   and  Great  Ormond   Street  Hospital,  London.    

Meeting  Dean  Andropolous  (Chief  of  Anesthesiology)  &  Emad  Mossad  (Director)  

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A  historical  perspective    There  is  a  great  sense  of  history  amongst  the  large  medical  center  complex  in  Houston.    Many   of   the   buildings   are   named   after   famous   innovative   physicians,   scientists   and  

surgeons.     I   visited   two   cardiac  museums  during  my  visit:  the  Michael  DeBakey  Library  &  Museum  and   the   Denton   Cooley   Museum.     These   two  surgeons  pushed   the  boundaries   and   carried  out  many   firsts   in   cardiac   surgery,   including  development   of   the   cardiopulmonary   bypass  machine,   the   design   of   Dacron   grafts   (e.g.   for  aortic   aneurysm   repair)   and   implantation   of   the  first   artificial   heart.     Looking   back   only   a   few  decades   on   these   achievements   highlighted   just  how   far   we   have   come   in   medicine   today.     And  how  far  things  will  go  in  the  decades  to  come.  

   A  future  perspective    I   had   an   opportunity   to   look   into   the   future   of   cardiac   surgery   during   visits   to   the  laboratory   of   Dr   Doris   Taylor.     Guided   round   by   Dr   Luiz   Sampaio,   a   surgeon   with  expertise   in   regenerative   medicine,   I   was   astonished   to   see   the   research   in   this  laboratory.    The  team  here   is  working  on  developing  beating  hearts  on  the   laboratory  bench-­‐top.    Their  paper  in  Nature,  published  in  2008  (2)  set  the  scene  for  the  future  of  cardiac   transplantation.     They   are  developing   a  process  of  decellularising  a  heart  so  as   to   leave  the  extracellular  matrix,  allowing  this  to  be  used  as  a  scaffold  which  can  then  be  populated  by  the  recipients  own  cadiomyocytes.  It  seems  feasible  that   by   the   end   of   my   career,   I   could   be  anaesthetising  patients  for  implantation  of  such    ‘custom  grown’  hearts.    The  research  was  simply  mind-­‐blowing  (3).      Thank  you    I  learned  a  great  deal  during  my  visit  to  the  Texas  Childrens  Hospital  and  it  is  a  trip  that  will   stay   with   me   for   a   long   time.   I   would   again   like   to   thank   the   Madeleine   Steele  Foundation   for   having  made   this   visit   possible.     I   hope   to   bring  many   of   the   lessons  learned  during  this  trip  to  my  practice  in  the  National  Health  Service.      Alyson  Walker  15th  June  2014  

Dr  Doris  Taylor  and  I  at  the  Texas  Heart  Institute  

Michael  DeBakey's  loops.

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 References  1. Andropolous  DB,   Stayer   SA,  Russell   IA,  Mossad  EB   (eds.).  Anesthesia   for  Congenital  Heart  Disease.  2nd  Edition.  Wiley-­‐Blackwell:  2010.  

2. Ott  HC,  Matthiesen  TS,  Goh  SK,  Black  LD,  Kren  SM,  Netoff  TI,  Taylor  DA.  Perfusion-­‐decellularised  matrix:  using  nature’s  platform  to  engineer  a  bioartifical  heart.    Nature  2008;14:213-­‐221.  

3. Dara  O’Briain’s  Science  Club.  Series  2.  Episode  2:  Adventures  in  Time.  London:  BBC;    1st  August  2013.    http://www.bbc.co.uk/programmes/p01dfkgd