Abstract
The ability to perform intraoperative cholangiography during laparoscopic cholecystectomy is an essential skill for the laparoscopic biliary surgeon. The volume of experience required to be able to consistently obtain a cholangiogram during laparoscopic cholecystectomy has not been determined. Cumulative sum analysis is a statistical technique which generates a graphical display that identifies periods of performance that fell below a predetermined standard for a given task. The cumulative sum (Sn) for a series of observations is defined as: ie185-001 where X1 = 0 for a success, X1 = 1 for a failure, and X0 is the acceptable failure rate for the process under study. This function is plotted against the number of observations to create a curve. When the curve has a positive slope, the acceptable failure rate is being exceeded. When it reaches a plateau, the observed failure rate is equal to the acceptable failure rate. When the curve has a negative slope, the observed failure rate is lower than the acceptable failure rate. We performed a cumulative sum analysis of the first 97 intraoperative cholangiograms attempted during laparoscopic cholecystectomy at our institution. The results demonstrated that 46 cases were required to reach a level of proficiency where a cholangiogram could be obtained in 95% of attempts. Success rates of 85% and 90% were achieved at 16 and 25 cases, respectively. This form of analysis is a useful tool for estimating the number of attempts required to achieve a desired success rate when learning new procedures.
Similar content being viewed by others
References
Williams SM, Parry BR, Schlup MMT. Quality control: An application of the CUSUM. Br Med J 1992;304:1359–1361.
Davies OL. The Design and Analysis of Industrial Experiments. London: Longman, 1978.
Kestin IG. A statistical approach to measuring the competence of anaesthetic trainees at practical procedures. Br J Anaesth 1995;75:805–809.
Hammond EJ, McIndoe AK. CUSUM: A statistical method to evaluate competence in practical procedures. Br J Anaesth 1996;77:562.
Bailey RW, Zucker KA, Flowers JL, Scovill WA, Graham SM, Imbembo AL. Laparoscopic cholecystectomy—Experience with 375 consecutive patients. Ann Surg 1991;214:531–541.
Airan M, Appel M, Berci G, Coburg AJ, Cohen M, Cuschieri A, Dent T, Duppler D, Easter D, Greene F, Halevey A, Ham-mer S, Hunter J, Jenson M, Ko ST, McFadyan B, Perissat J, Ponsky J, Ravindranathan P, Sackier JM, Soper N, Van Stiegmann G, Traverso W, Udwadia T, Unger S, Wahlstrom E, Wolfe B. Retrospective and prospective multi-institutional laparoscopic cholecystectomy study organized by the Society of American Gastrointestinal Endoscopic Surgeons. Surg Endosc 1992;6:169–176.
Wherry DC, Marohn MR, Malanoski MP, Hetz SP, Rich NM. An external audit of laparoscopic cholecystectomy in the steady state performed in medical treatment facilities of the Department of Defense. Ann Surg 1996;224:145–154.
Collet D. Laparoscopic cholecystectomy in 1994. Results of a prospective survey conducted by SCFERO on 4,624 cases. Surg Endosc 1997;11:56–63.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Molloy, M., Bower, R.H., Hasselgren, PO. et al. Cholangiography during laparoscopic cholecystectomy—Cumulative sum analysis of an institutional learning curve. J Gastrointest Surg 3, 185–188 (1999). https://doi.org/10.1016/S1091-255X(99)80031-6
Issue Date:
DOI: https://doi.org/10.1016/S1091-255X(99)80031-6