Using human reliability analysis to detect surgical error in endoscopic DCR surgery.

The aim of this study was to describe the nature of active skill-based errors occurring in endoscopic dacrocystorhinostomy (DCR) surgery. A human reliability analysis methodology was used to assess surgical error from observational capture data. Twelve endoscopic DCR operations performed by three different surgical trainees were video recorded. The steps (subtasks) of each operation were carefully analysed and common errors were documented. Specific errors that resulted in trauma to the nasal mucosa were noted. Execution errors were common, with errors of grasping being most frequent (67% of all execution errors). Most of these involved the Blakesley forceps. In total, there were 69 mucosal trauma hits. Inserting instruments into or withdrawing them from the nasal cavity with too much force or speed caused more than half of these. Incising with too much force resulting in 'overshoot' caused 34% of mucosal trauma. Trainee ENT surgeons should take particular care when inserting or withdrawing instruments from the nasal cavity and also when performing lacrimal sac or nasal mucosa incisions. Performance of these tasks with too much force was identified as a common and potentially avoidable cause of mucosal trauma. Further research is needed into the design and use of endoscopic sinus surgery instruments with the aim of avoiding the errors that were encountered.