In reference to Laser versus conventional fenestration in stapedotomy for otosclerosis: a systematic review.

In the article “Laser versus conventional fenestration in stapedotomy for otosclerosis: a systematic review,” Wegner et al. have reported a systematic review assessing hearing outcome and complications following primary stapedotomy in otosclerosis patients. We thank the authors for their effort in producing this work concentrating on an important clinical issue. However, there are a few comments that we would like to present. First, the authors report to have studied sensorineural hearing loss (SNHL), but a relevant definition is lacking. The American Academy of Otolaryngology– Head and Neck Surgery guidelines have defined SNHL as an increase in bone conduction (BC) pure-tone average (PTA) of 1, 2 and 4 kHz. When taking a closer look into the methods section of the eight shortlisted articles, none are reporting postoperative SNHL in compliance with these guidelines. In fact, seven different types of BC reporting can be observed (Table I; references in original article). Only two reports have used the same PTA, explained by the fact that they were submitted by the same group. Moreover, the study inclusion periods in the latter reports are overlapping: 1998 to 2001 and 1996 to 2000, respectively. Therefore, bias due to duplicate data cannot be excluded. The readers should at least be informed of this kind of heterogeneity to draw their conclusion based on raw data, for example, by providing the qualitative analysis as supplementary digital content. Second, we have observed that not every eligible study was included by the authors. Although we have not repeated the systematic review process per se, we have noticed at least one prospective study, reported by our group that was nor included or shortlisted. In this study, laser and conventional techniques were compared, whereas hearing outcome reporting was fully complying with the relevant guidelines. No statistically significant difference (SSD) was observed in SNHL at 3 months reported as percentage of 1, 2, and 4 kHz BC PTA over 15 dBHL. However, we observed a SSD in BC PTA difference favoring conventional techniques (i.e., 5 dBHL overclosure in conventional techniques and 1.25 dBHL when using the laser). Based on the abovementioned arguments, we do not agree with the authors’ second conclusion that laser should be preferred over conventional techniques because of less SNHL. At least one relevant study was excluded unduly, which might suggest the opposite. The authors’ first conclusion that both techniques are equivalent is reasonable, but outcome reporting demonstrates a considerable heterogeneity.