Intertransverse process block: A narrative review

The intertransverse process block (ITPB) is a general term for a class of novel thoracic paraspinal nerve block techniques proposed in recent years, which can be divided into the mid-point transverse process to pleura block, multiple-injection costotransverse block, costotransverse foramen block and the subtransverse process interligamentary plane block. The four types of ITPB all target the retro-superior costotransverse ligament space, but slightly differ in terms of needle entry approach and needle tip target. ITPB is easy to locate, quick to perform, and provides reliable analgesic effects. Furthermore, this technique can effectively reduce the risk of pneumothorax, hematoma and intraspinal injection. Thus, it has been gradually used for anesthesia and analgesia in breast, cardiothoracic, abdominal and spinal surgeries, as well as for pain relief in trauma patients. However, due to the limited evidence base, its safety and efficacy remain inadequately understood, and few clinicians are proficient in performing ITPB. Further large-scale randomized controlled trials are required to validate its feasibility and superiority. This narrative review will summarize the anatomical basis, mechanism, operation methods, clinical application and shortcomings of ITPB to provide new ideas for multimodal analgesia.