Cadaveric investigation of the spread of the thoracoabdominal nerve block using the perichondral and modified perichondral approaches

Interfascial plane blocks and associated nomenclature are currently popular topics in the field of anesthesia. While several novel plane blocks have been described, cadaveric studies on the spread of novel blocks are important for determining appropriate applications [1]. Recently, Tulgar et al. [2] defined the thoracoabdominal nerve block using a perichondral approach (TAPA). They reported that local anesthetic (LA) administered on the upper and lower aspect of the 9th through the 10th costal cartilages would block both the anterior and lateral cutaneous branches, thus providing abdominal analgesia. After describing the TAPA, the authors also redefined the approach, naming it the modified TAPA (M-TAPA). They reported that administering LA only to the lower surface of the costal cartilage would provide successful analgesia similar to that provided by the TAPA [3]. In the literature, there are some case reports and observational studies on the TAPA and M-TAPA [2,3]; however, to the best of our knowledge, no reliable cadaveric investigation has demonstrated the spread of these blocks. Therefore, in this cadaveric investigation, we aimed to evaluate the areas of spread associated with the TAPA and M-TAPA. This study was approved by the Istanbul Medipol University Ethics and Research Committee (Decision No. 36, 06.01.2022).