Dear Editor,

We thank Professor Xue for his kind comments on our recently published article “Comparison of Thoracoscopy-Guided Thoracic Paravertebral Block and Ultrasound-Guided Thoracic Paravertebral Block in Postoperative Analgesia of Thoracoscopic Lung Cancer Radical Surgery: A Randomized Controlled Trial” [1]. They raised several questions of great significance to our research. So we hope to help readers better understand our research through this reply.

First of all, we must admit that the concern highlighted by Prof. Xue is reasonable. Prof. Xue mentioned that we did not clearly describe whether the experience of the anesthesiologist and surgeon performing the thoracic paravertebral block (TPB) was comparable. He was concerned that an unbalanced level of experience would have biased the primary outcomes in favor of the thoracoscopy-guided technique. It is true that we did not mention whether the doctors who performed TPB were skilled or experienced. However, we mentioned at the end of Sect. “Study Design and Population” that the surgery and anesthesia procedures were performed by the same experienced team. The team has worked together perfectly for more than 10 years. Thoracic surgery and thoracoscopy-guided thoracic paravertebral block (TTPB) were performed by Dr. He. Our team combined the technical principle of thoracoscopic-guided intercostal nerve block [2] and the principle of ultrasound-guided thoracic paravertebral block (UTPB), designed and confirmed the safety and effectiveness of TTPB technology [3, 4]. Dr. He has rich experience in the TTPB operation since 2020 [3, 4]. The UTPB was performed by Dr. Xu, who has been engaged in anesthesiology for 18 years and has mastered the operation of UTPB. Therefore, the TPB operations of the two groups in this study were performed by experienced physicians. TTPB and UTPB are two different approaches of TPB, performed by thoracic surgeons and anesthesiologists, respectively. So we cannot guarantee the balance of their experience levels. We can only ensure that they have rich experience to reduce bias. This does not affect the rigor of this study.

Secondly, this study aims to compare the application of TTPB and UTPB in terms of surgical simplicity, surgical time, success rate of the first puncture, and analgesic effect after thoracoscopic lung cancer radical surgery. However, this study did not focus on opioid retention analgesia strategies, so postoperative opioid analgesia strategies were still incorporated. This does not affect the validity of the research results. Moreover, our research team has conducted research on the application of TTPB in postoperative analgesia with fewer opioids or without opioids entirely, and has achieved preliminary results. We find that TTPB can replace patient-controlled intravenous analgesia (PCIA) for postoperative analgesia after single-port thoracoscopy surgery, achieving a strategy of postoperative analgesia without opioid drugs. If the editor is interested, we are also willing to submit the relevant research manuscript to this journal. The time point observed in this study lasted until 48 h after surgery, and the duration of action of PCIA was also 48 h. Neither group received rescue analgesia after surgery, so there was no significant difference in the consumption of opioid drugs and the number of analgesic rescue between the two groups. At the same time, the comparison of VAS scores between the two groups in this study was sufficient to reflect the postoperative analgesic effect. Considering the main purpose of this study, we did not include the consumption of postoperative opioid drugs and analgesic rescue in this manuscript. Of course, adding these two indicators would also make the research results more convincing.

Thirdly, the surgical time of TPB in the TTPB group was significantly shorter than that in the UTPB group (2.2 ± 0.3 vs. 5.7 ± 1.7 min, t = − 12.411, P < 0.001). But Prof. Xue mentioned that difference of procedure time between-group only was 3.5 min, which was clinically insignificant. TTPB does not require additional disinfection and sterile drapes. It is easy to find the area where the needle needs to be inserted under direct view of thoracoscopy. So the surgical time of TTPB is shorter. However, we mentioned in Sect. “Data Collection” that the surgical time for a block in the UTPB group was considered from the placement of the ultrasound probe on the chest wall to the completion of the drug injection. When performing UTPB surgery in clinical practice, the operator also needs to disinfect the hands and wear sterile surgical gowns. The chest and back areas need to be re-disinfected and covered with sterile wipes, and the ultrasound probe needs to be covered with sterile protective covers. These steps require a significant amount of time. If the surgical time of UTPB in this study is combined with the aforementioned time, it will be much greater than 3.5 min. The success rate of the block is a crucial factor affecting its effectiveness and can be affected by various factors such as block difficulty, technical proficiency, surgical space, and imaging level. The success rate of the first puncture of UTPB performed by experienced anesthesiologists in this study is still lower than that of TTPB. If the doctors are not proficient enough, the success rate may be even lower. The surgical time and success rate of the first puncture of TPB are sufficient to distinguish the difficulty of TTPB and UTPB operations.

Finally, we deeply thank Prof. Xue again for his contribution to this discussion. Prof. Xue is a highly respected anesthesiologist and we are glad to receive his attention and comments. We believe that his comments have added further insights to this study.