Conceptual advances have been made in understanding the nature and limits of human performance.
The application of these findings to high-risk activities, such as commercial aviation, has allowed restructuring of the work environment to reduce human error.
In this study, researchers from the United States applied human performance concepts in order to understand causes, and prevention, of laparoscopic bile duct injury.
The research team analyzed 252 laparoscopic bile duct injuries using principles of cognitive science; visual perception, judgment, and human error.
Injury distribution was class I 7%, class II 22%, class III 61%, and class IV 10%.
|Faults in technical skill were present in only 3% of injuries.|
|Annals of Surgery|
The team also used data from operative radiographs, clinical records, and 22 videotapes of original operations.
The researchers determined that the primary cause of error in 97% of cases was a visual perceptual illusion.
Faults in technical skill were present in only 3% of injuries.
In addition, knowledge and judgment errors were contributory but not primary.
Overall, 25% of injuries were recognized at the index operation. However, the surgeon identified the problem early enough to limit the injury in only 6% of cases.
The team found that in class III injuries the common duct, erroneously believed to be the cystic duct, was deliberately cut. This was due to an illusion of object form due to an uncommon configuration of the ducts, and the unconscious assumptions of human visual perception.
Videotapes showed the persuasiveness of this illusion, and many operative reports described the operation as routine.
Class II injuries resulted from a dissection too close to the common hepatic duct.
Fundamentally an illusion, this was contributed to in some instances by working too deep in the triangle of Calot.
Dr Lawrence Way's team concluded, "Errors leading to laparoscopic bile duct injuries stem principally from misperception, not errors of skill, knowledge, or judgment".
"The misperception was so compelling that in most cases the surgeon did not recognize a problem".
"Even when irregularities were identified, corrective feedback did not occur, which is characteristic of human thinking under firmly held assumptions".
"These findings illustrate the complexity of human error in surgery while simultaneously providing insights".
"They demonstrate that automatically attributing technical complications to behavioral factors that rely on the assumption of control is likely to be wrong".
"There are only a few points within laparoscopic cholecystectomy where the complication-causing errors occur, which suggests that focused training to heighten vigilance might be able to decrease the incidence of bile duct injury".