A Learning Curve in Bentall and De Bono Procedure with the Use of the Risk-Adjusted Cumulative Sum Analysis Based on the Japan SCORE


  • Min-Ho Song




Objective: The risk-adjusted cumulative sum analysis of an individual surgical learning curve for the Bentall and De Bono procedure on aortic root pathologies was used to monitor and enhance quality control.

Methods: From April 2004 to March 2009, 20 consecutive patients were operated upon by a single surgeon for aortic root pathologies by means of the Bentall and De Bono procedure. Operative variables, mortality, and major morbidities were analyzed. The learning curve was calculated using descriptive statistics and cumulative sum failure observed minus expected failure rate derived from the Japan SCORE calculator.

Results: In this series, the Japan SCORE calculator expected 3.91% ± 5.14% of 30-day operative mortality rate and 16.74 ± 13.47% of 30-day operative mortality and morbidity. In reality, there was no operative and in-hospital death. Major postoperative morbidity rate was 15.0% (3 patients). The risk-adjusted cumulative sum analysis revealed that the learning curve of mortality was downward below the lower 95% confidence interval throughout all the patients and that of morbidity was upward till the seventh case and remained downward thereafter. The polynomial approximation coefficient analysis revealed a significant negative correlation between aortic cross-clamp time, cardiopulmonary time, and operation time and case load.

Conclusions: The Bentall and De Bono procedure for aortic root pathologies was performed at the professionally permissive level from the beginning, even in a low-volume environment. It showed one good example of a learning curve. The risk-adjusted cumulative sum analysis based on the Japan SCORE was a very useful tool for monitoring the performance.


Bentall H, De Bono A. 1968. A technique for complete replacement of the ascending aorta. Thorax 23:338-9.nDe Paulis R, De Matteis GM, Nardi P, et al. 2002. One-year appraisal of a new aortic root counduit with sinuses of Valsalva. J Thoracic Cardiovasc Surg 123:33-9.nHannan EL, Wu C, Ryan TJ, et al. 2003. Do hospitals and surgeons with higher coronary artery bypass graft surgery volumes still have lower riskadjusted mortality rates? Circulation 108:795-801.nHolzhey DM, Jacobs S, Walther T, Mochalski M, Mohr FW, Falk V. 2007. Cumulative sum failure analysis for eight surgeons performing minimally invasive direct coronary artery bypass. J Thorac Cardiovasc Surg 134:663-9.nKouchoukos NT, Marshall WG Jr, Wedige-Stecher TA. 1986. Eleven-year experience with composite graft replacement of the ascending aorta and aortic valve. J Thorac Cardiovasc Surg 92:691-705.nNovick RJ, Fox SA, Stitt LW, et al. 2002. Assessing the learning curve in off-pump coronary artery surgery via CUSUM failure analysis. Ann Thorac Surg 73:S358-62.nRathore SS, Epstein AJ, Volpp KG, Krumholz HM. 2004. Hospital coronary artery bypass graft surgery volume and patient mortality, 1998-2000. Ann Surg 239:110-7.nRogers CA, Reeves BC, Caputo M, Ganesh JS, Bonser RS, Angelini GD. 2004. Control chart methods for monitoring cardiac surgical performance and their interpretation. J Thorac Cardiovasc Surg 128:811-9.nShahian DM, Normand SL. 2003. The volume-outcome relationship: from Luft to Leapfrog. Ann Thorac Surg 75:1048-58.nSioris T, David TE, Ivanov J, Armstrong S, Feindel CM. 2004. Clinical outcomes after separate and composite replacement of the aortic valve and ascending aorta. J Thorac Cardiovasc Surg 128:260-5.nSong MH, Tajima K, Watanabe T, Ito T. 2005. Learning curve of coronary surgery by a cardiac surgeon in Japan with the use of cumulative sum analysis. Jpn J Thorac Cardiovasc Surg 53:551-6.nSong MH, Tokuda Y, Hirai M, Ueda Y. 2007. Learning curve of arch-first technique analyzed by cumulative sum. Asian Cardiovasc Thoracic Ann 15:507-10.nSong MH, Tokuda Y, Nakayama T, Hattori K. 2008. A simple method of inspection of proximal bleeding in Bentall procedure. Asian Cardiovasc Thorac Ann 16:329-30.nSong MH, Tokuda Y, Nakayama T, Hattori K, Hirai M. 2008. Safe launching of a newly appointed cardiac surgery unit at a low-volume hospital with the use of cumulative sum analysis. Circ J 72:437-40.nSong MH, Tokuda Y, Ueda Y. 2007. A novel method for proximal suturing of Carbo-Seal: aorta folded-over technique. Gen Thorac Cardiovasc Surg 55:270-1.nUeda Y, Osada H, Osugi H; Japanese Association for Thoracic Surgery Committee for Scientific Affairs. 2007. Thoracic and cardiovascular surgery in Japan during 2005. Annual report by the Japanese Association for Thoracic Surgery. Gen Thorac Cardiovasc Surg 55:377-99.nWelke KF, Barnett MJ, Sarrazin MS, Rosenthal GE. 2005. Limitations of hospital volume as a measure of quality of care for coronary artery bypass graft surgery. Ann Thorac Surg 80:2114-9.n



How to Cite

Song, M.-H. (2011). A Learning Curve in Bentall and De Bono Procedure with the Use of the Risk-Adjusted Cumulative Sum Analysis Based on the Japan SCORE. The Heart Surgery Forum, 14(6), E380-E383. https://doi.org/10.1532/HSF98.20111053