Single-Injection Midpoint Transverse Process-to- Pleura Block Versus Thoracic Paravertebral Block for Postoperative Analgesia After Uniportal Video-Assisted Thoracoscopic Surgery: A Randomized Controlled Trial

Abstract

Objectives: The effect of midpoint transverse process-to-pleura block (MTPB) is unclear. The authors compared the analgesic characteristics of MTPB with those of thoracic paravertebral nerve block (TPVB) in patients undergoing uniportal video-assisted thoracoscopic surgery (uVATS) and examined the 2 types of blocks for noninferiority.

Design: A randomized, controlled trial.

Setting: A single-institution, university hospital.

Participants: The study comprised 82 patients between 18 and 75 years of age. Eighty-one patients were included for final analysis.

Interventions: Patients were randomly allocated to either the MTPB group (Group M) or the TPVB group (Group P).

Measurements and main results: The primary outcome was the mean difference in the postoperative visual analog scale (VAS) score between Group M and Group P at rest and at 12 hours. The secondary outcomes included VAS scores during rest and coughing, nerve block performance, intraoperative consumption of anesthetics and vasoactive medication, time at first use of patient-controlled intravenous analgesia (PCIA), number of uses of PCIA, consumption of sufentanil in PCIA, and side effects. The mean difference in VAS score in the MTPB and TPVB group at rest and 12 hours postoperatively was 0.5 (95% confidence interval, -0.26 to 0.36). There was no significant difference in the time at first use of PCIA, which was 12 (10, 12) hours and 11 (10, 12) hours in Group M and Group P, respectively. The depth of puncture was shallower, and the time to perform block was shorter in Group M compared with Group P (p < 0.001).

Conclusions: The analgesic effect of single-level-injection MTPB is noninferior to that of TPVB in patients undergoing uVATS. The target point of the needle in MTPB is shallower and farther away from the pleura compared with TPVB. For these reasons, it is quicker and safer and, thus, may be preferable.

Keywords: mid-point transverse process to pleura block; postoperative analgesia; single injection; thoracic paravertebral block; uniportal video-assisted thoracoscopic surgery.