An error is a failure of a planned action to achieve a desired goal [14]. Training in error prevention has been well established and researched in high-risk industries such as aviation, space travel, the military, nuclear plants, and oil rigs [1]. However, there has been little research in why and how errors occur in surgery [3, 5, 12, 18, 19]. In particular, surgery is a high-risk specialty, and as has been shown, it may have a detrimental effect on patients, with one study quoting an annual incidence rate of adverse events among patients having an operation as 3.0%, of which half were preventable [17].

However, most of these studies concentrate on pre and postoperative adverse events and do not reflect on surgical technical skill errors and why they may occur. There have been some studies which explore factors affecting the execution of technical tasks [2, 4, 8, 9, 13, 15, 16]. These studies concentrate on well-known stresses that cause technical skills performance to decay. There have been only a few technical error studies [6, 7, 10] exploring experienced surgeons performing real operations with no detrimental stresses affecting them. As in the Bristol cardiac cases, technical skills in highly complex operations were shown to directly influence surgical outcome.

Consultant revalidation is imminent in the General Medical Council. At present there is no formal assessment of the technical skills of a consultant surgeon. Consultant laparoscopic surgeons are highly trained technicians. Most professional, and lay people would expect a low technical error rate in such a group of surgeons.

However, laparoscopic surgery may inherently have a constant technical error rate even in highly trained individuals. In this study we assess generic and procedure-specific minor and major technical skill error rates in laparoscopic cholecystectomies performed by consultant/attending surgeons.

Methods

Checklists of generic (Table 1) and specific technical minor and major events (Table 1) were devised for laparoscopic cholecystyectomy. These were devised after panel. expert discussion and literature reviewing [6, 7, 10, 11, 20] and from the Joint Committee in Higher Surgical Training in General Surgery in the UK assessment form for technical skills. The entire operation (internal) was recorded and converted to DVD. Assessment of the external environment (operating-room teamwork) was not video recorded, but recorded using a checklist on all the major aspects of the teamwork required to perform a laparoscopic cholecystectomy. The prospective study was conducted at the ACAD Centre, Park Royal, London, which is an overnight stay hospital. All the patients satisfied day care requirements and were ASA 1–2 and had a BMI < 30. All of the consultant surgeons had performed more than 150 laparoscopic cholecystectomies previously. All the surgeons had more than 7 hours’ sleep and had no time pressure on completing the cases. Two experienced surgeons with more than 12 years of postgraduate experience assessed each full-length operation blindly and independently. They also graded the laparoscopic cholecystectomies using a clinco-pathological grade of 1–5 (Table 1).

Table 1 (a) Generic skills checklist
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Table 2 (b) Specific technical skills checklist—minor errors
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Table 3 (c) Specific technical skills checklist—major errors
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Results

There were 25 female 12 male patients in the study; mean age was 56 years (range 26–64). Mean BMI was 26 (range 21–29). A total of 37 laparoscopic cholecystectomies were performed by eight consultants. Five consultants contributed five cases, and the other three, four cases. There were no major intraoperative or postoperative complications and no conversions to open. The patients were followed postoperatively. All of the gallbladders were graded between 1 and 2 in the study using the 5 grade scale by the independent assessors. Twenty gallbladders were graded 1 and 17 were graded 2. Mean operation time for the surgeons was 25 min (range 14–40 min). The external environment (operating-room teamwork) did not have any detrimental effect on the operation.

Mean inter-rater reliability was κ = 0.91 p < 0.05 (range 0.80–0.98) for each of the error categories between the two independent blinded assessors of technical skills using the checklists for generic, minor, and major technical skill errors. Error rates were for generic (27/407) 6.6%, for minor (59/222) 26.6% and for major (8/296) 2.7%, respectively. The numbers in parentheses are the total number of errors committed out of a possible limit in each category using the checklists. Each error group was then compared. Using the Student paired test there was a significant statistical difference between the minor error group and the generic and major error groups, p ≤ 0.05. There was no significant difference between each individual surgeon, clinico-pathological grade of the gallbladder, or operation time.

Discussion and Conclusions

Surgical error has been recently a topical issue within the medical community and the public. There have been several studies that illustrate adverse events occurring to surgical patients [3, 5, 12, 18, 19]. These studies demonstrate the errors occurring in the pre- and postoperative care of these patients. However, there has been little research on real-time error analysis of the operative environment and execution of errors regarding technical skills [6, 7, 10].

The recognition and the execution of errors is part of normal human behavior. Performing laparoscopic surgery involves a complex cascade of psychomotor skills. While performing such highly technical tasks, it may be very difficult not to commit some errors when executing tasks and subtasks. Therefore laparoscopic surgery may always have a background technical error rate (generic, minor, and major) due to its technical intricacy.

Our present study demonstrates a gradation of surgical technical errors performed by expert surgeons (consultant surgeons). The surgeons execute a high rate of minor errors, which have little consequence. However, when it comes to the major fundamental aspects of the operation, they perform fewer major technical errors. As expected, the surgeons perform a low level of generic skill errors, as these are acquired through experience.

Figure 1 is a hypothetical model of how errors may occur in the operating-room. The three core aspects of surgical competency are depicted (technical skill, decision making, team performance). The model was devised using this data on technical skill error, and the decision-making and team-performance aspects on unpublished data from our department. The majority of surgical cases are uneventful with minor errors occurring throughout the surgical process. However, for example, if there was a major bleeding occurring due to a technical error the graph would migrate to the danger zone. If this is not corrected the patient may suffer an adverse event. But if the bleeding is corrected without significant blood loss the graph goes back to the normal level.

Figure 1
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Model of fluctuations of surgical errors.

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We aim to continue the study to increase the number of cases, assess trainees, and also explore other factors that may affect the surgeon when executing surgical technical tasks.