Investigating the Learning Curve in Endoscopic Compared to Microscopic Myringotomy and Ventilation Tube Insertion

By June 7, 2019

Denton, Oliver1; Daglish, Amy2; Smallman, Luke1; Edwards, Dan3; Ahmed, Jake4; Snow, David4; Smith, David5; Fishpool, Sam5
1 Cardiff University, Cardiff, UK;
2 Oxford University Hospitals NHS Foundation Trust, Oxford, UK;
3 Aneurin Bevan UHB, Newport, UK;
4 Betsi Cadwaladr UHB, Wrexham, UK;
5 Cwm Taf UHB, Ynysmaerdy, Pontyclun, UK.

Introduction:
Rate of learning is often cited as a deterrent in the use of endoscopic ear surgery. The study aims to characterise and compare the learning curves of novice surgeons performing myringotomy and ventilation tube insertion on a surgical simulator, using either an endoscope or a microscope.

Methods:
Prospective clinical research study set across four British district general hospitals. Surgically naïve Welsh medical students (n=72) were randomly allocated to either the endoscope or microscopic group, and were timed in performing 10 myringotomy and ventilation tube insertions on a surgical simulator using their assigned technique.

Discussion:
Trial times were used to produce learning curves. From these, the slope (rate of learning) and asymptote (optimal proficiency) were ascertained and compared across the two groups. There was no significant difference between the learning curves (p=0.41). The best potential procedure time (seconds) was calculated to be 32.83 for the microscope and 27.87 for the endoscope. The learning rate in the microscope group was 68.62, whilst that for the endoscope group was 78.71, where a larger value represents a slower rate of learning.

Conclusion:
The absence of a significant difference infers that the learning rates of each technique are statistically indistinguishable. This suggests that surgeons are not justified when citing a ‘steep learning curve’ in arguments against the use of endoscopes in middle ear surgery.