In Reply:
We received a commentary by Gebhard et al.1 on our systematic review and meta-analysis of the benefits of Pectoralis-II fascial block for breast cancer surgery.2 In their comments, the authors claim to have found it “extremely difficult to verify the quality and integrity of the data.”
This difficulty is partly based on the assumption that every outcome reported to be assessed in table 1 (Characteristics of Included Studies) should also appear in the Results section. Unfortunately, this assumption is not true, and the involved scenarios are numerous. For example, included trials (1) seldom assess an outcome without explicitly reporting its numerical results; or (2) do not report results of an outcome in a format that permits data extraction; or (3) simply state that the two groups were not different for an outcome, without providing further explanation. While we routinely contact authors of such trials seeking additional details, and often obtain valuable input, having studies with outcomes that were assessed but that were not included in the quantitative analysis is sometimes inevitable. In contrast, some outcomes (e.g., opioid consumption) may not be explicitly reported as an outcome, but it can still be deduced from the description of the analgesic regimen and hence included in the quantitative analysis. Authors of meta-analyses know that the quality and integrity of data are not affected by such scenarios.
Furthermore, Gebhard et al. claim that the noninferiority conclusion is based on a comparison involving 83 patients only. Again, this claim is not justified because it is based on selective exclusion of four clinical trials that had met the criteria for inclusion in this review. Excluding four studies should be based on strong justifications, which Gebhard et al. do not provide.
The Editor’s Perspective accompanying our review also receives criticism. We find this unnecessary; a careful reader of our article will find our conclusion to be meticulously stated: “[I]t is important to confine the conclusion to the specific settings where the comparisons were conducted. Pectoralis-II is not clinically worse (noninferior) for analgesic outcomes to single-injection paravertebral block in patients having breast surgery procedures involving the axilla.” This finite and very specific statement renders the suggestion of overstating results unreasonable.
Finally, the “strong feeling” of Gebhard et al. that no conclusions can be drawn from the data may have been biased by their stated belief that multilevel paravertebral block is superior to single-level paravertebral block, which is debatable. There is evidence from a recent clinical trial indicating that single-level paravertebral block provides analgesia (and dermatomal spread) that is equivalent to multilevel paravertebral block.3 Moreover, many practitioners continue to use single-level paravertebral block to provide postoperative analgesia for breast surgery. Consequently, the comparison of a single-level paravertebral block with single-injection Pectoralis-II block is a valid clinical and research question.
Competing Interests
The authors declare no competing interests.
