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A new ultrasonic process for a renewal of aortic valve decalcification
https://doi.org/10.1186/1476-7120-4-2
© Aubert et al; licensee BioMed Central Ltd. 2006
Received: 21 October 2005
Accepted: 05 January 2006
Published: 05 January 2006
Abstract
Background
Aortic valve decalcification by ultrasound was given up. We evaluated a new ultrasound microhandpiece (Dissectron Penstyle®) to rehabilitate this alternative treatment.
Methods
We used under magnifying lenses the ultrasound microhandpiece to decalcify 30 explanted aortic valves. In the cases with embedded calcifications the thin top of the probe could be introduced into the thickness of the leaflet preserving covering layers.
Results
The leaflets were totally decalcified and flexible, and surrounding structures were preserved as assessed by histological examination.
Conclusion
This new approach of ultrasonic aortic valve decalcification gives good in vitro results which allow to consider a clinical evaluation of this procedure.
Keywords
Background
The aortic valve debridement by ultrasound in degenerative-calcific aortic stenosis appeared to be an alternative treatment for severe calcified aortic stenosis [1], but was given up because of the high incidence of restenosis and aortic regurgitation [2, 3]. The aim of this study was to rehabilitate aortic valve decalcification by a new probe: the microhandpiece Dissectron Penstyle®. This probe is more handy and more precise than the previous ones. Therefore the reintroduction of valve decalcification by ultrasound is envisageable.
Methods
Penstyle micro handpiece with his micro sonotrode: length 192 mm, weight 60 gr, end diameter of the top 1.45 mm, used as a pen.
Results
Aortic valve before and after decalcification.
A: Aortic valve before decalcification, an arrow indicates an impressive bulky calcification deposit; B: Aortic valve after decalcification, an arrow indicates a cavity instead of the calcification. This valve is not totally decalcified (3+).
A: Leaflet with embedded calcification, B: The probe into the thickness of the leaflet preserving covering layers.
Histological section of an aortic leaflet after decalcification, an arrow indicates a remaining cavity. A: Ventricular side, B: Aortic side.
Discussion
The penstyle handpiece was totally adapted to decalcify aortic valves quickly, with comfort and precision. Although the initial results of the ultrasound decalcification with the previous probes in aortic stenosis were impressive [4, 5] two principal problems were observed: early occurrence of aortic insufficiency and significant incidence of restenosis [2, 3]. Aortic insufficiency was caused by leaflet retraction and the loss of central coaptation thought to be secondary to the healing response [3]. The aortic restenosis was caused by the accumulation of calcium in the remaining fibrillar structure [6]. The excursion of our tip was 110 μm comparatively to the 154 μm excursion of the Cavitron® used by McBride [7]. As the Penstyle® handpiece decalcifies in better conditions than those previously described [8], with a lower level of mechanical energy, we expected a decreased healing response and consequently a decreased occurrence of aortic insufficiency. There is not any biological effects of our ultrasounds on the normal tissue, therefore we can use our probe safely in a therapeutic approach. The 1.54 mm end diameter of the Penstyle® was extremely precise to decalcify, rendering subsequent damaging of the normal valvular tissue around the calcium limited. The thin top of the probe allowed decalcification within the thickness of the leaflets without destroying the covering layers. The use of magnifying lenses facilitated an accurate procedure. This new approach of decalcification damages the valve as little as possible, so we hope to decrease the risk of early recalcification of the remaining valve. The ultimate test is the longevity of the improved flexibility and function in the patient, so we plan a clinical trial in patients to verify these two parameters. Lastly, we must distinguish two groups: calcific lumps on the aortic surface of the cusps favourable for ultrasound decalcification and embedded calcifications requiring an indispensable complementary treatment of the remaining cavities predisposing to early recalcification. The proposed indication for this new approach is a coronary bypass grafting associated with a stenosis of the aortic valve, when we hesitate to replace the valve. The expected advantage is to avoid a further operation to replace the aortic valve, with all the risks of a redo-operation.
Conclusion
This new approach of ultrasonic aortic valve decalcification was efficient to decalcify all the valves whatever the degree of calcification. Calcific lumps on the aortic surface of the cusps are favourable for this treatment. The mainly pitfall of our technique is to avoid to decalcify embedded calcifications. Even if it is possible to decalcify this sort of calcification, the remaining cavity will be recalcified very quickly. Only a clinical evaluation of this procedure will demonstrate a decreased risk of both recalcification and secondary aortic regurgitation.
Declarations
Authors’ Affiliations
References
- Enright LP, Hancock EW, Shumway NE: Aortic debridment:long-term follow-up. Circulation 1971, 43: 68-72.View ArticleGoogle Scholar
- Craver JM: Aortic valve debridement by ultrasonic surgical aspirator: a word of caution. Ann Thorac Surg 1990, 49: 746-52.View ArticlePubMedGoogle Scholar
- Cosgrove DM, Ratliff NB, Schaff HV, Edwards WD: Aortic valve decalcification: history repeated with a new result. Ann Thorac Surg 1990, 49: 689-90.View ArticlePubMedGoogle Scholar
- Kellner HJ, Pracki P, Hildebrandt A, Binner C, Eisele G, Struck E: Aortic valve debridement by ultrasonic surgical aspirator in degenerative, aortic valve stenosis: follow-up with Doppler echocardiography. Eur J Cardiothorac Surg 1996, 10: 498-504. 10.1016/S1010-7940(96)80414-3View ArticlePubMedGoogle Scholar
- Baeza OR, Majid NK, Conroy DP, Donahoo JS: Combined conventional mechanical and ultrasonic debridement for aortic valvular stenosis. Ann Thorac Surg 1992, 54: 62-7.View ArticlePubMedGoogle Scholar
- Dahm M, Dohmen G, Groh E, Groh E, Krummenauer F, Hafner G, Mayer E, Hake U, Oelert H: Decalcification of the aortic valve does not prevent early recalcification. J Heart Valve Dis 2000, 9: 21-26.PubMedGoogle Scholar
- McBride LR, Naunheim KS, Fiore AC, Harris HH, Willman VL, Kaiser JC, Pennington DG, Labovitz AJ, Barner HB: Aortic valve decalcification. J Thorac Cardiovasc Surg 1990, 100: 36-42.PubMedGoogle Scholar
- Eguaras MG, Saceda JL, Luque I, Concha M: Mitral and aortic valve decalcification by ultrasonic energy. Experimental report. J Thorac Cardiovasc Surg 1988, 95: 1038-40.PubMedGoogle Scholar
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