Letter to the Editor: “Role of Topical Tranexamic Acid on Blood Loss and Transfusion Requirements in Spinal Fusion for Neuromuscular and Syndromic Scoliosis”

Dear Editor,

We read with great interest the recent article by Conde et al ¹ entitled “Role of Topical Tranexamic Acid on Blood Loss and Transfusion Requirements in Spinal Fusion for Neuromuscular and Syndromic Scoliosis”. They analyzed peri-operative blood loss and changes in hemoglobin following posterior spinal fusion (PSF) for neuromuscular and syndromic scoliosis (NMS) by comparing the 2 groups without TXA as a topical immersion sponge (tTXA) and with tTXA, respectively. It is concluded that administration of tTXA-soaked sponges is an effective and safe method to reduce intraoperative blood transfusion requirements in the correction of spinal deformity in patients with NMS. Our panel of professional peers have some suggestions and questions they would like to share with the authors after reading their excellent and valuable articles:

First, the design of the control group was particularly important in this study as a retrospective case-control study. In a similar study by Maethungkul et al, ² the case group was the same as in this study, but the control group was a sponge that received the same volume of saline-soaked sponge wrapped around the surgical wound. This was different from that study where a dry sponge was wrapped in the surgical wound as a control group. They came up with a different result than this study, which was that there was no difference in postoperative blood loss or transfusion requirements between the tTXA group and the placebo group. So I would like to ask the authors if they can give a brief comment as to whether the difference in results for this kind of study should be taken into account in relation to the design of the control group?

Second, for the outcome variables of this study, the results of postoperative hemoglobin (Hb) and hematocrit (Hct) differed from the conclusions of Ren ³ and Guo, ⁴ although the authors briefly explained in the Discussion section that it might be possible that this result appeared due to the fact that the control group had received a higher number of intraoperative blood product transfusions, it was not convincing. We therefore suggest that the authors might be able to further analyze the reasons for the emergence of the discrepant results by comparing the rate of change of Hb and Hct on the 3 days of POD1, POD2, and POD3.

In addition, the outcome variables in this study focused on specific metrics such as total blood loss, occult blood loss, intraoperative blood loss, and total postoperative drainage volume. Other potential factors that may contribute to the interpretation of the study results, such as plasma TXA levels, routine postoperative coagulation monitoring, postoperative thromboelastography monitoring, and other parameters were not included in the analysis. In the trial conducted by Huang et al ⁵ on TXA, a statistically significant prothrombin time international normalized ratio was found, so it may be better to combine some plasma TXA levels and coagulation parameters to assess the impact of local TXA application on intraoperative transfusion requirements in PSA.

It is worth noting that the sample size included in this retrospective study may be relatively small and also not within the same time period, which may affect the accuracy and representativeness of the findings to some extent.

Conde et al

Finally, we thank Conde et al for their contributions to the field of surgical treatment of NMS, and we hope that our comments will help readers to better read this article.