Aortic Valve Replacement through Upper Partial Sternotomy versus Full Median Sternotomy. Single Center Experience

Aim. Minimally invasive aortic valve replacement (AVR) through upper partial sternotomy has many benefits including stability of thoracic cage because of maintained lower part of sternum. Our aim was to determine whether stability of thoracic cage leads to better pulmonary outcome for patients after AVR through upper partial sternotomy compare to patients after AVR through full median sternotomy.
Methods. From April 2013 to December 2013 in our heart surgery department were performed 58 isolated AVR operations. All these patients were divided into two groups- AVR- through upper partial L-shaped sternotomy (through fourth or fifth intercostal space)- 22 (37,9%) patients and AVR through full median sternotomy 36 (62,1%). The mean age in the group with partial sternotomy was (mean±SD) 63,13±17,20 years (range 28-86 years) and in the group with full sternotomy was (mean±SD) 65,09±16,02 (range 29-85 years). Spirometry was performed before operation and before discharge from hospital. All statistical analysis was performed with IBM SPSS Statistics 22. Statistical significance was considered at the level of p<0,05. Data are given as mean± standard deviation (SD).
Results. Both groups were similar in age (p=0,328), preoperative left ventricular ejection fraction (p= 0,266), aortic valve area (p=0,384), mean pressure gradient through aortic valve (p= 0,466), chronic heart failure classes (p=0,837), EuroScore II (p=0,494), glomerular filtration rate (p=0,836).
Preoperative forced vital capacity was 92,73±19,34% of predicted in group with partial sternotomy and 76,57±26,27% of predicted in full sternotomy group, and there were no significant difference (p=0,551). But postoperative FVC in partial sternotomy group was 68,27±15,46 and in full sternotomy group was 64,73±17,51. Percent of predicted preoperative forced expiratory volume in 1 second (FEV1) in partial sternotomy group preoperatively was 87,85±24,65 and postoperatively decreased to 63,38±16,41. Percent of predicted FEV1 in full sternotomy group before and after operation changed from 74,93±24,67 to 65,85±20,48. Changes in FVC and FEV1 after operation were not statistically different among both groups (p=0,524 and p=0,978).
Also we didn`t find any significant difference in operation time 185,22±38,45 vs 155,63±17,82 (p=0,245), cardiopulmonary bypass time 103,57±33,81 vs 86,97±20,24 (p=0,190) and aortic cross-clamp time 68,26±19,60 vs 58,57±14,78 (p=0,871).
Maximum troponin level was significantly higher in full sternotomy group 16,06±21,98 compare to partial sternotomy group 11,36±7,99 (p=0,027).
There were no significant difference in mean pressure gradient through prosthetic valve in both groups (p=0,949).
Also there were no significant difference in hospital stay among both groups (p=0,444).
Conclusion. AVR through upper partial sternotomy can be performed in the same quality as through full median sternotomy. Despite we didn`t find any new benefits of partial sternotomy, we think that reduced surgical trauma, more stable thoracic cage, smaller wound are reasons to prefer upper partial sternotomy for aortic valve replacement.