Ann Thorac Surg 2002;74:1113-1114
© 2002 The Society of Thoracic Surgeons
Original article: cardiovascular
Invited commentary
Thomas A. Orszulak, MDa
a Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA
e-mail: thomas{at}mayo.edu
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Introduction
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The article by Bach and colleagues describes the impact of implant techniques on outcomes of the Freestyle stentless porcine prosthesis. Although the inclusion technique may be used successfully, only 38 patients underwent this type of implantation and were not evaluated due to small numbers. The distilled version of the data concluded that late aortic regurgitation was more frequent with the subcoronary technique than with full root. This is not surprising when the intricate details of the aortic root are considered. When the subcoronary technique is used, the geometry of the sinotubular junction of the donor prosthesis is specific to the individual heart that it serves (human and porcine). When one structure is altered (sinotubular junction divided by resection of one or more sinuses) and is placed into an unrelated recipient aortic root, it should not be a surprise that the leaflets may not be competent [1, 2].
On the other hand, the root replacement approach carried a considerable increase in operative mortality, although it did eliminate late aortic regurgitation in the survivors. The median age was not quoted but could be assumed to be over 70 by the statistical results and Tables 1 and 3. It is always important to compare a new technology with a tried and true treatment modality, which in this situation is valve replacement. To keep it in the bioprosthetic theme, we are speaking of stented porcine or pericardial valves, since this has been, and I feel is, the standard treatment especially in patients over the age of 70 years. The relevant data for comparison would be operative mortality and freedom from valve related morbidity [3, 4].
A final editorial comment regarding what cardiothoracic surgeons must think about, is whether we should submit patients to a lethal learning curve for a procedure that has not been shown to be better even when the learning curve is complete? The aortic regurgitation did not fail to appear with the second 100 cases and the operative mortality did not fall. We could argue that one hospital sees sicker patients, but in light of one’s always performing a subcoronary or full root replacement in one’s population base, it would seem more likely that the goal was to test the prosthesis—not perform the best procedure for the patient.
I do not have the answer to training residents in techniques that are new and perhaps untested or letting them obtain their learning curve after they leave the protection of a training institution. I believe that we as surgeons need to be cautious of what techniques we subject our patients to in the guise of the advancement of science, without a critical appraisal of when and where it should be used. I am not proposing new technology nihilism, but when an extremely safe surgical procedure is available, we should study all aspects of any "advancement" that is developed without sacrificing good results and patient lives.
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References
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- Staab M.E., Nishimura R.A., Dearani J.A., et al. Aortic valve homografts in adults: a clinical perspective. Mayo Clin Proc 1998;73:231-238.[Medline]
- Dearani J.A., Orszulak T.A., Daly R.C., et al. Comparison of techniques for implantation of aortic valve allografts. Ann Thorac Surg 1996;62:1069-1075.[Abstract/Free Full Text]
- Morris J.J., Schaff H.V., Mullany C.J., et al. Determinants of survival and recovery of left ventricular function after aortic valve replacement. Ann Thorac Surg 1993;56:22-30.[Abstract]
- Orszulak T.A., Schaff H.V., Mullany C.J., et al. Risk of thromboembolism with the aortic Carpentier-Edwards bioprosthesis. Ann Thorac Surg 1995;59:462-468.[Abstract/Free Full Text]
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Introduction
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