Every drop counts: blood conservation in conventional versus minimally-invasive aortic valve replacement
Minimally Invasive aortic valve replacement (mini-AVR) via upper partial sternotomy is increasingly become routine. Minimizing the surgical trauma to the thoracic cage from minimally invasive procedures has been shown to shorten hospital stay, recovery time, surgical morbidity and sternal wound complications. We compared the use of blood products between conventional and minimally-invasive approaches to isolated aortic valve replacements. There is a perception that less surgical aggression driven by mini-invasive techniques accounts for a smaller amount of blood loss and may contribute to decreased mortality/morbidity associated with transfusions and bleeding re-explorations
1.Mini-sternotomy via J-shaped incision
2.Aortic & Venous Cannulation
4.Explantation & Decalcification
5.Implantation of AVR
6.Closure of aortotomy
10.Haemostasis & Wire Closure
Operative records between 2006 and 2015 were examined to retrieve all patients who had undergone MIAVR (Group 1). This was compared against a sample of isolated conventional first-time AVR (con-AVR) (Group 2). Patient selection was according to surgeon preference. Group 1 was undertaken by one surgeon using mini-AVR for all patients with isolated first-time AVR. Group 2 was undertaken by 5 surgeons using median sternotomy for all isolated first-time AVR. The cardiac surgery database was accessed to get all details. A retrospective analysis of the two unmatched cohorts was undertaken. Survival data was obtained from the national patient details registry (Welsh Demographic Service). Blood usage was obtained from the blood bank database. SPSS v22 was used to undertake unpaired t-test with 95% confidence intervals where appropriate to analyze the results
Our series demonstrates:
•The patients were matched pre-op for age, sex, haemoglobin, BMI and renal functions.
•There was less requirement of blood transfusion in mini-AVR group given that their pre-op haemoglobin was with in the same range.
•There were significantly less re-openings in mini-AVR group which was statistically significant thus having:
ØLow burden of post-operative complications
ØLow burden of blood transfusion requirements
ØLow burden of post-operative length of stay
•Reduction of post-operative bleeding and the need for blood transfusions are the two most commonly mentioned benefits of MIAVR
Future directions – compare quality of life, sub-group analyses of groups with increased morbidity (i.e. BMI, LV function, COPD, other aortic procedures).
From our experience of 200 miAVR we have shown that there is significant reduction in blood transfusion and re-exploration for bleeding once compared to the patients undergoing converntional AVR.