Comment On: “Effectiveness of Combining Thoracic Paravertebral Nerve Block and Serratus Anterior Plane Block in Non-Intubated Spontaneous-Ventilation Video-Assisted Thoracoscopic Surgery: A Retrospective Case-Control Study” [Letter]

Dear editor

We read with interest the retrospective study that assessed the combination of the thoracic paravertebral block (TPVB) and the serratus anterior plane block (SAPB) in video-assisted thoracoscopic surgery (VATS), and would like to provide a few clarifications.

Shi et al concluded that the combination of TPVB and SAPB resulted in a significant reduction in opioid requirement and inflammatory markers when compared to these two blocks applied alone.¹ However, adding these two blocks is unnecessary as the TPVB provides sensory coverage of the entire hemithorax and is therefore inclusive of sensory coverage of the anterolateral part of the hemithorax alone provided by the SAPB.² A recently published study could not find any significant difference between the combination of TPVB and SAPB versus TPVB alone.³ Shi et al did not critically analyze these two referenced articles^2,3 (reference numbers 24 and 27 of Shi et al¹) and instead wrote some vague points on these two references.

Based on the above-mentioned concepts, the results of the current study raise a few questions. First, it is intriguing that the combination of two blocks resulted in significant differences when compared to TPVB alone. Second, it is highly questionable that the SAPB group performed better than the TPVB group despite the partial sensory coverage provided by the SAPB. Third, the inflammatory markers are not routinely performed in all the cases undergoing VATS, that too at various time intervals as specified. Hence, we are surprised that details of inflammatory markers of all the cases could be available to the authors during their retrospective analysis.