Re: Lange R, Hoerer J, Schreiber C. What are the obstacles to training in surgery for congenital heart disease in Germany? Thorac Cardiovasc Surg 2013;61:273–277

The current situation of congenital heart surgery in Germany is indeed interpellating. As reminded by Lange and coauthors, the minimal number of 250 procedures per year and at least 100 operations in infants has been stated by the Congenital Heart Disease Committee of the European Association of Cardio-Thoracic Surgery and the German Society for Thoracic and Cardiovascular Surgery. Accordingly, low-volume institutions are referred to disappear to ensure quality.

One can argue that departments managing a small number of procedures can achieve excellent results, even if these outcomes bear large confidence intervals. Moreover, expected quality should vary in conformity with the complexity of performed procedures.

We recently proposed to use the newly defined concept of “unit performance” to fix the minimal requirements for a congenital heart surgery program.[1] Procedure complexity is estimated by the Aristotle basic complexity (ABC) score. Postoperative 30-day or hospital survival multiplied by yearly mean ABC score gives the surgical performance achieved yearly by the unit. Unit performance is the product of surgical performance multiplied by the number of primary procedures that are performed.

Lacour-Gayet et al[2] reported surgical performances ranging from 5.67 to 6.90 with a mean of 6.3 ± 0.4. With a minimum of 250 primary procedures per year, required minimal unit performance would therefore be 1,575. This threshold could be reached by fewer than 250 cases, provided that performed operations bear higher ABC score and are successful. For example, the two centers mentioned by DeCampli and Burke[3] with surgical performances of 7.57 and 7.38 would need 208 and 213 procedures per year, respectively, to satisfy this requirement. Units managing mainly less complex lesions and achieving lower figures of surgical performance would have to carry out more procedures to attain the 1,575 level. Thus, with a surgical performance of 5.80 as published by Dilber and Malcic,[4] the number of operations would be at least 272 per year.

To sustain quality and to facilitate adequate training in congenital heart surgery, minimal surgical case load alone does not suffice. Agreement to a minimal value of unit performance (here 1,575 points) would allow to match quality and quantity by taking into account complexity of lesions, survival after surgery, and the number of performed procedures.

• References

• 1 Arenz C, Asfour B, Hraska V , et al. Congenital heart surgery: surgical performance according to the Aristotle complexity score. Eur J Cardiothorac Surg 2011; 39 (4) e33-e37
• 2 Lacour-Gayet F, Clarke D, Jacobs J , et al; Aristotle Committee. The Aristotle score: a complexity-adjusted method to evaluate surgical results. Eur J Cardiothorac Surg 2004; 25 (6) 911-924
• 3 DeCampli WM, Burke RP. Interinstitutional comparison of risk-adjusted mortality and length of stay in congenital heart surgery. Ann Thorac Surg 2009; 88 (1) 151-156
• 4 Dilber D, Malcic I. Evaluation of paediatric cardiosurgical model in Croatia by using the Aristotle basic complexity score and the risk adjustment for congenital cardiac surgery-1 method. Cardiol Young 2010; 20 (4) 433-440