Efficacy of the intertransverse process block: single or multiple injection? A randomized, non-inferiority, blinded, cross-over trial in healthy volunteers

Abstract

IntroductionThe intertransverse process block is increasingly used to ameliorate postoperative pain following a plethora of surgical procedures involving the thoracic wall. Nevertheless, the optimal approach and cutaneous extent of the sensory block are currently unknown. We aimed to further describe the intertransverse process block, single injection versus multiple injection, and we hypothesized that the single-injection intertransverse process block is a non-inferior technique.MethodsTwelve healthy male volunteers were cross-over randomized to receive either single-injection intertransverse process block with 21 mL ropivacaine 7.5 mg/mL, including two sham injections, at the thoracic level T4/T5 or multiple-injection intertransverse process block with three injections of 7 mL ropivacaine 7.5 mg/mL at the thoracic levels T2/T3, T4/T5 and T6/T7 at the first visit. At the second visit, the other technique was applied on the contralateral hemithorax. A non-inferiority margin of 1.5 anesthetized thoracic dermatomes was chosen.ResultsThe mean difference (95% CI) in the number of anesthetized thoracic dermatomes was 0.82 (−0.41 to 2.05) pnon-inf<0.01 indicating non-inferiority favoring the single-injection technique.Both techniques anesthetized the ipsilateral thoracic wall and demonstrated contralateral cutaneous involvement to a variable extent. The multiple-injection intertransverse process block anesthetized a significantly larger cutaneous area on the posterior hemithorax and decreased mean arterial pressure at 30 and 60 min postblock application. Thoracic thermography showed no intermodality temperature differences yet compared with baseline temperatures both techniques showed significant differences.ConclusionsSingle-injection intertransverse process block is non-inferior to multiple injection in terms of anesthetized thoracic dermatomes. Both techniques generally anesthetize the hemithoracic wall to a variable extent.EU clinical trials register2022-501312-34-01.

Thoracic Erector Spinae Plane (T-ESP) Block Together With Intertransverse Process (ITP) Block for Laparoscopic Abdominal Surgery: A Case Report

“…The ITP block is applied on the posterior side of the TPVS (retro-SCTL space) [ 15 ] in a modality described as paravertebral block by proxy. A single-injection ITP block has shown to be non-inferior to multiple injections in terms of anesthetized dermatomes demonstrating an involvement to a variable extent up to four levels [ 16 ]. In a real-life clinical practice study, which reflects the clinical reality more accurately than autopsy studies, Chen et al [ 17 ] found that compared with the ESP block, a single-injection ITP block yielded increased stability in the lateral and anterior chest wall block with improved anterior and intercostal spread although with a reduced cephalocaudal spread.…”

Combined thoracic erector spinae plane and inter‐transverse plane blocks for awake breast surgery

“…The inter-transverse plane block is delivered to the posterior aspect of the thoracic paravertebral space (retro-superior costo-transverse ligament space), and is described as a `paravertebral-by-proxy´block [11]. A single-injection inter-transverse plane block has been demonstrated to be non-inferior in comparison to multiple injections in terms of anaesthetised dermatomes [12]. Chen et al observed that, compared to the erector spinae plane block, a single-injection inter-transverse plane block provides enhanced anterior and intercostal spread, albeit with reduced cephalocaudal spread [13].…”