Bone removal
There are indications which exist for microscopic surgery which preclude
total EES; for example, if cholesteatoma is present within the mastoid
cavity proper, then microscopic ear surgery is recommended for removal
of disease.2 All mastoid procedures were carried out
within our microscopic group (Table 1). This raises the question of
whether differing degrees of bone removal account for the difference in
pain scores between endoscopic and microscopic groups. Similarly,
Kakehata et al. , also reported mastoid surgery only within the
microscopic group.4 To overcome this, they conducted
subgroup analysis between procedures with no bony removal and those with
varying degrees of removal. Between these subgroups, no significant
difference was detected in pain scores, and it was concluded that bony
removal has no influence over pain scores. We also carried out a
subgroup analysis based on bone removal and no statistically significant
result was found between pain scores between groups. As this subgroup
analysis was underpowered (n=1) in the microscopic non-bone removal
group), this was not included within our main results (Supplementary
Table 2, Supplementary Figure 1). It is therefore difficult to make any
statement about the influence of bone removal on our results.