Mini-sternotomy versus conventional sternotomy for aortic valve replacement: a randomised controlled trial

OBJECTIVE: To compare clinical and health economic outcomes after manubrium-limited mini-sternotomy (intervention) and conventional median sternotomy (usual care). DESIGN: A single-blind, randomised controlled trial. SETTING: Single centre UK National Health Service tertiary hospital. PARTICIPANTS: Adult patients undergoing aortic valve replacement (AVR) surgery. INTERVENTIONS: Intervention was manubrium-limited mini-sternotomy performed using a 5–7 cm midline incision. Usual care was median sternotomy performed using a midline incision from the sternal notch to the xiphisternum. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the proportion of patients who received a red cell transfusion postoperatively and within 7 days of index surgery. Secondary outcomes included proportion of patients receiving a non-red cell blood component transfusion and number of units transfused within 7 days and during index hospital stay, quality of life and cost-effectiveness analyses. RESULTS: 270 patients were randomised, received surgery and contributed to the intention to treat analysis. No difference between mini and conventional sternotomy in red-cell transfusion within 7 days was found; 23/135 patients in each arm received a transfusion, OR 1.0 (95% CI 0.5 to 2.0) and risk difference 0.0 (95% CI −0.1 to 0.1). Mini-sternotomy reduced chest drain losses (mean 181.6 mL (SD 138.7) vs conventional, mean 306·9 mL (SD 348.6)); this did not reduce red-cell transfusions. Mean valve size and postoperative valve function were comparable between mini-sternotomy and conventional groups; 23 mm vs 24 mm and 6/134 moderate or severe aortic regurgitation vs 3/130, respectively. Mini-sternotomy resulted in longer bypass (82.7 min (SD 23.5) vs 59.6 min (SD 15.1)) and cross-clamp times (64.1 min (SD 17.1) vs 46·3 min (SD 10.7)). Conventional sternotomy was more cost-effective with only a 5.8% probability of mini-sternotomy being cost-effective at a willingness to pay of £20 000/QALY (Quality Adjusted Life Years). CONCLUSIONS: AVR via mini-sternotomy did not reduce red blood cell transfusion within 7 days following surgery when compared with conventional sternotomy. TRIAL REGISTRATION NUMBER: ISRCTN29567910; Results.