Study selection and data retrieval
The search results are shown in the PRISMA diagram (Fig. 1). The initial
screening identified 611 studies. Of these, 584 search results were
excluded during the preliminary screening because they were unrelated or
duplicated. The remaining 27 full-text manuscripts were retrieved, and a
further 12 studies were excluded based on our inclusion and exclusion
criteria. Fifteen studies evaluating four different regional anesthesia
techniques were finally included for quantitative and qualitative
analysis.16-30
The regional and local anesthesia techniques included the
pecto-intercostal fascial (PIF), transversus thoracis muscle plane
(TTMP), erector spinae plane (ESP), and pectoralis nerve (PECS) I blocks
( Fig. 2).
The 15 included studies were randomized to 849 patients. Of these, 405
patients were allocated to placebo or no intervention, 183 to the PIF
block, 148 to the TTMP block, 93 to the ESP block, and 20 to the PECS I
block.
According to the risk of bias evaluation, four studies had a low risk of
bias, two had a high risk of bias, and some concerns arose with the
remaining studies (Supplementary Material, File 2). The criteria that
guided us in assigning the risk of bias judgments are available as
supplementary material (Supplementary Material, File 3).