A prospective multi-institutional study to verify the non-inferiority of postoperative pain in robot-assisted thoracic surgery in comparison with video-assisted thoracoscopic surgery for lung cancer: The Japanese RATS interest group 01 (J-RATSIG 01)

Objectives

We sought to compare the latest data on postoperative pain between robot-assisted thoracic surgery (RATS) and video-assisted thoracoscopic surgery (VATS), and to clarify the relationship between the number or placement of ports and postoperative pain in patients with lung cancer.

Methods

Patients who underwent anatomical lung resection by RATS or VATS and whose chest tube was removed within 7 days were enrolled. The primary endpoint was the percentage of patients with a numeric rating scale (NRS) score ≤ 3 on postoperative day 30 (POD30). The target sample size was 400 patients.

Results

Four hundred five patients (RATS, n = 196; VATS, n = 209) managed at 12 institutions were included. Ninety-nine patients in the VATS group underwent a uniport procedure. Significant differences were observed between the RATS and VATS groups in the mean number of inserted ports (5.0 vs. 2.2), number of injured intercostal sites (2.9 vs. 1.9), largest wound size (3.4 vs. 3.7 cm), operation time (202 vs. 165 min), and use of epidural anesthesia or continuous nerve block (45 vs. 31 %). In the RATS and VATS groups, the rates of NRS≤3 on POD30 were 82.0 % and 94.7 % (95 %CI: −19.0 to −6.6 %), respectively, which could not prove noninferiority. However, in a multivariable analysis, the RATS approach was not proven to be a significant risk factor.

Conclusion

In the current status of minimally invasive thoracic surgery in Japan, RATS involves a greater number of ports, longer operation time, and higher frequency of local anesthesia than VATS and may be inferior in terms of postoperative pain.