Minimally Invasive Surgery
Surgical mitral valve repair is the gold standard for treating primary
MR and around 95% of patients being treated in designated centres while
the remaining 5% who are not suited for surgery, will be considered for
one of the aforementioned transcatheter interventions. Its effectiveness
on secondary MR is still disputed and current European guidelines
encourage pharmacological management.56
Traditionally, surgical repair/replacement of the mitral valve was done
via median sternotomy. In order to minimise mortality and morbidity,
various minimally invasive approaches have been developed, but
undoubtedly the most common approach is right
minithoracotomy.56-58 A small incision is made in the
4th intercostal space, providing access to the heart.
The intervention requires access to femoral vessels for peripheral
cannulation and connection to a cardiopulmonary bypass machine (CPB).
TEE is used for guidance. Wolfe et al present in great detail the
surgical technique and the four pillars of a successful minimally
invasive mitral valve surgery (MIMVS): adequate cannulation and
perfusion, good view of the mitral valve, thorough cardiac protection
and procedure match to specific pathology and aetiology of MV
defect.58
For correction of degenerative MR, one of the most prevalent MV
pathologies, great results have been recorded using a non-resectional
repair technique and implantation of new chordae using the loop
technique, accompanied by ring annuloplasty for better resilience in the
long-term. MV repair in the case of endocarditis is based on the removal
of infected tissue and the use of a pericardial patch or repair using
primary suturing, along with artificial chordae implant and ring
annuloplasty. Annuloplasty with a closed, undersized ring is also used
in the operation for ischemic MR.57, 59,60
Less perioperative complications (especially blood loss), decreased
chances of surgical wound infection, as well as a shorter recovery
period, have been the main advantages of
MIMVS.57,61,62 Operative survival rate in multiple
retrospective studies has been 100% and mortality rate at 30-day follow
up is between 0.2 to 4.8%, depending on patient profile, higher
mortality being recorded for patients undergoing MIMVS with concomitant
tricuspid valve repair or coronary artery bypass
grafting.60,63,64 Disadvantages of MIMVS, compared to
standard sternotomy, include longer CPB time and increased risk of
stroke during or immediately after intervention (almost 2.6% of
patients have reported ischemic strokes).59