Surgical Outcome of Minimal Invasive Mitral Valve Replacement

Abstract

Background:
Mitral valve repair and replacement depends on cardiopulmonary bypass and techniques of repair and replacement
are improving continuously and a lot of surgeons contributed to the development of this field.
Aim of study:
- To determine whether minimally invasive mitral valve surgery improves clinical outcomes compared with
conventional open mitral valve surgery in patients undergoing mitral valve replacement.
- To analyze the learning curve of the surgeon who has started performing minimally invasive mitral valve
surgery at our institution and to provide recommendations on the necessary experience to achieve and retain highquality outcomes in this field.
Patients and Methods:
This is a prospective study of 26 patients who underwent mitral valve replacement in Al Najaf Center for Cardiac
Surgery and Trans Catheter Therapy from August 2015 to October 2016, 16 patients underwent isolated mitral valve
replacement through a minimally invasive approach and 10 patients underwent isolated mitral valve replacement
through a conventional sternotomy.
Statistical analysis was done by using SPSS (statistical package for social sciences) version 20. In which we use
frequencies, percentages and mean as descriptive statistics. T-test, paired t-test , and Yates corrected chi square had
been used according to type of variable. P value <0.05 regarded significant.
Result:
MICS was done in 16 patients (61.5%) while the remaining underwent conventional sternotomy.There was no
reopening for bleeding for all patient with MIMVS while in conventional sternotomy 2 patients (20%) had been
reopened for bleeding. In conventional sternotomy wound infection was seen in 2 patients (20%) while in MIMVS no
infection had been reported. There are no significant differences in postoperative echocardiographic finding between
MIMVS and conventional sternotomy approach.
Discussion:
In conventional sternotomy wound infection was seen in 2 patients (20%) while in MICS no infection had been
reported. while in similar study done by Schmitto et al(57)wound infection in sternotomy group5.7% and 0.9% in
MIMVS group. This difference may be explained by additional risk of groin complication associated with MIMVS
group in their study .
Minimally invasive mitral valve surgery patients commonly are extubated earlier and have a shorter hospital stay
(mean=6.5days) than conventional sternotomy patients (mean=12.2days) which is similar to another study done by
Svensson et al(59) in Cleveland Research Institute ,Ohio, in which the mean postoperative length of hospital stay was
6days after MIMVS , and 10.3 days after conventional sternotomy. The decreased intensive care unit and total hospital
length of stay ,the faster physical rehabilitation, and consequently less use of hospital resources, all these make
MIMVS cost effective and cost saving strategy for mitral valve surgery compared with traditional approach . The
mortality rate after MIMVS versus conventional sternotomy was similar at 30 days (0 %).It is compared with another
study done by Glauber et al (55) which was the same mortality at 30 days but different at 1year,5year
mortality(2.1%,1.7% respectively)the only explanation is limited number of cases and short duration of our study.
Conclusion:
MIIMVS has been proven to be a feasible alternative to the conventional full sternotomy approach with low
perioperative morbidity and short-term mortality.
Recommendation:
Mitral valve replacement through a small thoracotomy is technically demanding. Therefore, screening out patients
who are not appropriate for performing minimally invasive surgery is the first step. Vascular disease and inadequate
anatomy can be evaluated with contrast-enhanced computed tomography. Peripheral cannulation should be
carefully performed. Valve replacement can be performed in minimally invasive surgery as long as
cardiopulmonary bypass is stable and bloodless exposure of the valve is obtained