Lesser impairment of respiratory function is the mechanism of faster recovery after partial sternotomy for valve replacement: Reply

Abstract

We thank Sim and Grignani for their interest in our study showing improved results in 40 patients undergoing aortic valve replacement (AVR) with the ministernotomy (MS) approach [1Bonacchi M. Prifti E. Giunti G. Frati G. Sani G. Does ministernotomy improve postoperative outcome in aortic valve operation? A prospective randomized study.Ann Thorac Surg. 2002; 73: 460-466Abstract Full Text Full Text PDF PubMed Scopus (192) Google Scholar]. They obtained faster recovery and better pulmonary function in 9 patients undergoing an inverted J MS than in 10 patients who had a conventional incision. All patients had preoperative and early postoperative spirometry. Sim and Grignani believe that preserved stability of the sternum results in less respiratory dysfunction and better and faster recovery of lung function postoperatively. Their data are comparable to ours [1Bonacchi M. Prifti E. Giunti G. Frati G. Sani G. Does ministernotomy improve postoperative outcome in aortic valve operation? A prospective randomized study.Ann Thorac Surg. 2002; 73: 460-466Abstract Full Text Full Text PDF PubMed Scopus (192) Google Scholar] despite the different MS. Also, Sim and Grignani analyzed respiratory recovery during only the immediate postoperative period (to the morning of the third postoperative day). One of the main limitations of our series is the small number of patients in the preliminary study [1Bonacchi M. Prifti E. Giunti G. Frati G. Sani G. Does ministernotomy improve postoperative outcome in aortic valve operation? A prospective randomized study.Ann Thorac Surg. 2002; 73: 460-466Abstract Full Text Full Text PDF PubMed Scopus (192) Google Scholar]. To date, 50 patients having aortic valve replacement are enrolled prospectively in the study, and we believe that this number will increase. We analyzed a series of postoperative respiratory and spirometric variables related to the functional status of the “thoracic-pulmonary system.” These include incidence of prolonged mechanical ventilation, inspired oxygen fraction, gas analyses, pressure assistance, maximum inspiratory pressure, maximum expiratory pressure, and forced expiratory volume in 1 second. The measurements are done at various stages in the respiratory recovery process. We believe that such analyses provide a clear view of the postoperative respiratory functional status in this pool of patients. However, for a better understanding of respiratory improvement, preoperative and postoperative mechanical respiratory tests are required; thus, we examined especially the maximum inspiratory and expiratory pressures. These variables seem to be very sensitive to thoracic-pulmonary system dysfunction. According to our data, these two variables return to preoperative status within 1 month after operation in patients undergoing an MS, whereas in patients undergoing a conventional sternotomy, complete recovery occurs during the third postoperative month. In our study, we found that patients undergoing an MS have less bleeding and postoperative pain, shorter intensive care unit and hospital stays, and consequently, reduced operation costs. Therefore, we believe that with additional training and a short learning curve, surgeons can use the MS approach and thereby realize enormous advantages for their patients. Although some studies find only a slight advantage [3Svensson L.G. D’Agostino R.S. Minimal-access aortic and valvular operations, including the “J/j” incision.Ann Thorac Surg. 1998; 66: 431-435Abstract Full Text Full Text PDF PubMed Scopus (56) Google Scholar] and others demonstrate no difference [4Aris A. Cámara M.L. Montiel J. Delgado L.J. Galán J. Litvan H. Ministernotomy versus median sternotomy for aortic valve replacement a prospective, randomized study.Ann Thorac Surg. 1999; 67: 1583-1588Abstract Full Text Full Text PDF PubMed Scopus (111) Google Scholar, 5Aris A. Does ministernotomy improve postoperative outcome in aortic valve operation? A prospective randomized study.Ann Thorac Surg. 2002; 73 ([invited commentary]): 465-466Abstract Full Text Full Text PDF Scopus (1) Google Scholar] in recovery between MS and full-length incision, our experience provides enough data for further discussions and more studies with larger numbers of patients. We congratulate Sim and Grignani on their results and thank them for their contribution regarding this challenging and controversial topic. We find their comments useful for increasing the consensus within the cardiac surgical community for the minimally invasive approach philosophy [2Sellke FW, Cohn WE. CT Digest 2002;4(3):review 7Google Scholar].