Thoracic epidural versus paravertebral blockade for reducing chronic post-thoracotomy pain (TOPIC-2): an open-label, allocation-concealed, multicentre, randomised controlled trial

Importance

Many patients undergoing thoracotomy suffer from debilitating chronic post-thoracotomy pain (CPTP) lasting months or years postoperatively. The effectiveness of the commonly used two analgesic techniques, paravertebral blockade (PVB) and thoracic epidural blockade (TEB), on the incidence of CPTP is unknown.

Objective

To test the hypothesis that PVB reduces the incidence of CPTP compared with TEB.

Design

Pragmatic, open-label, allocation-concealed randomized controlled trial. Participants were recruited between January 8th, 2019 and September 29th, 2023.

Setting

15 UK thoracic centers.

Participants

770 eligible adult patients undergoing thoracotomy were randomly assigned (1:1) to TEB or PVB using a web-based randomization service.

Intervention(s)

Participants in the PVB group received three single-shot paravertebral injections of local anesthetic before knife-to-skin, followed by placement of a paravertebral catheter. Participants in the TEB group had a thoracic epidural catheter placed and loaded with local anaesthetic before knife-to-skin.

Main Outcome(s) and Measure(s)

The primary outcome was the incidence of CPTP at 6 months post-randomization, defined as a 100mm Visual Analogue Score (VAS) greater than or equal to 40mm (indicating moderate pain) when considering ‘worst chest pain over the last week’. Secondary outcomes included additional measures of chronic/acute pain, complications and quality of life.

Results

The trial enrolled 770 patients (342 female patients (44.4%); mean (SD) age, 66.6 (11.0) years). After 33 post-randomisation exclusions of patients who did not proceed to thoracotomy, 737 were included in the modified intention-to-treat population (364 PVB, 373 TEB). At 6-months, 59 (22%) of 272 participants in the PVB group and 47 (16%) of 292 participants in the TEB group developed CPTP (adjusted risk ratio=1·32 [95%CI 0·93 to 1·86]; adjusted risk difference=0·05 [95%CI –0·01 to 0·11]; p=0·12). During the acute phase, pain was greater on day 1 with PVB, but not different on days 2-3. Hypotension was less common in the PVB group; complications were similar otherwise.

Conclusions and Relevance

PVB did not reduce the incidence of CPTP at 6 months compared to TEB. TEB appeared to provide marginally better acute pain relief on postoperative day 1, but there was no difference thereafter. Postoperative complications were comparable between groups. The findings support the ongoing utility of both techniques.

Trial Registration

This trial is registered with ClinicalTrials.gov, NCT03677856 .

Funding Organisation

NIHR HTA reference-16.111.111

Key Points