Thoracoabdominal nerves block through the perichondrial approach: a narrative review

The Thoracoabdominal nerves block using the perichondrial approach (TAPA) was first described by Tulgar et al. as a trunk nerve block technique designed to provide analgesia for abdominal surgery. Subsequently, the modified TAPA (M-TAPA) was proposed, in which a local anesthetic was injected only at the lower aspect of the costal cartilage. More recently, a re-modified TAPA was developed to achieve a more consistent blockade of the lateral cutaneous nerve branches. Despite increasing clinical adoption of the TAPA and its modifications, many important details remain insufficiently understood. In this review, we provide a comprehensive update on the available cadaveric and clinical studies of the TAPA and its modifications. The PubMed, Embase, and Web of Science databases were searched, and 276 studies of interest were identified. After excluding irrelevant articles, 75 studies were finally included in the review. The literature indicated that, among these techniques, the M-TAPA has been extensively studied. The anterior sensory coverage achieved by the M-TAPA was marginally better and more stable than its lateral coverage. The TAPA and its modifications are applicable to surgery in the abdominal and inguinal regions. Single-shot and continuous infusions have been described. To date, no complications associated with these blocks have been reported. Thus, the various TAPA blocks are promising techniques. Randomized controlled trials of high methodological quality are required to elucidate the roles of these techniques further.