TY  - CHAP
M1  - Book, Section
TI  - Mitral Valve Replacement
A1  - Huddleston, Stephen J.
A1  - Yuh, David D.
A2  - Yuh, David D.
A2  - Vricella, Luca A.
A2  - Yang, Stephen C.
A2  - Doty, John R.
PY  - 2014
T2  - Johns Hopkins Textbook of Cardiothoracic Surgery
AB  - Prosthetic  valve  designDesign  of  both  mechanical  and  bioprosthetic  valves  has  continued  to  evolve  since  the  invention  of  the  first  valve  to  improve  flow  dynamics,  reliability,  and  durability,  while  minimizing  thrombogenicity  and  avoiding  structural  valve  dysfunction  (SVD).IndicationsMitral  valve  (MV)  surgery  is  recommended  for  symptomatic  acute  severe  mitral  regurgitation  (MR),  chronic  severe  MR  with  New  York  Heart  Association  (NYHA)  class  II,  III,  or  IV  symptoms  and  no  severe  left  ventricular  (LV)  dysfunction,  and  asymptomatic  patients  with  mild-to-moderate  LV  dysfunction  and  severe  MR.  MV  surgery  is  reasonable  for  asymptomatic  severe  MR  in  some  cases.  Mitral  replacement  in  the  setting  of  MR  should  be  performed  when  repair  is  not  possible  or  the  functional  result  would  be  inadequate.The  indications  for  MV  replacement  in  mitral  stenosis  are  the  following:  (1)  moderate  (mean  valve  area  ≤1.5  cm2)  or  severe  MS  (mean  valve  area  ≤1.0  cm2)  and  NYHA  functional  class  III  or  IV  symptoms  if  they  are  not  candidates  for  percutaneous  balloon  valvotomy  or  MV  repair;  and  (2)  severe  MS  with  moderate-to-severe  MR  in  symptomatic  patients.  MV  replacement  may  be  indicated  for  patients  with  severe  MS  with  pulmonary  hypertension  and  NYHA  class  I  or  II  symptoms.Treatment  (surgical)The  choice  of  prosthetic  valve  type  is  rooted  in  an  understanding  of  valve  features  that  determine  thrombogenicity  (the  need  for  anticoagulation)  and  durability,  as  these  factors  relate  to  patient  characteristics.The  most  appropriate  surgical  approach  to  the  MV  is  determined  by  patient  characteristics  and  surgeon  expertise.  Typically,  a  median  sternotomy,  right  thoracotomy,  or  mini  right  thoracotomy  is  employed.  Aortic  or  femoral  arterial  cannulation  and  bicaval  or  femoral  venous  cannulation  is  performed  depending  on  the  incision.  Venting  may  be  performed  through  the  aortic  root  and  left  atrium  or  left  ventricle  across  the  valve,  and  cardioplegia  is  given  antegrade  and  retrograde.  The  valve  may  be  exposed  through  a  transverse  incision  in  the  left  atrium  or  through  a  transseptal  approach.The  chordal  sparing  technique  of  MV  replacement  improves  LV  function  and  survival.  Valve  stitches  may  be  everting  or  noneverting.Warfarin  therapy  with  a  goal  INR  of  2.5  to  3.5  is  indicated  after  MV  replacement  with  a  mechanical  prosthesis.  Early  anticoagulation  for  patients  with  bioprosthetic  MVs  is  controversial.Outcomes/prognosisMV  replacement  can  be  performed  with  outstanding  efficacy,  and  risk  is  proportional  to  patient  and  surgical  risk  factors  that  can  be  assessed  using  well-established  risk  scoring  systems.  Acute  surgical  complications  typically  arise  from  problems  with  cardiopulmonary  bypass  or  a  combination  of  technical  mistakes  and  patient  factors.  Late  complications  are  rare  and  usually  include  prosthetic  valvular  endocarditis,  thrombosis/anticoagulation,  or  SVD.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accesssurgery.mhmedical.com/content.aspx?aid=1104590463
ER  -