Subcostal TAP block versus M-TAPA block as an adjunct to lateral TAP block in robot-assisted prostatectomy: a retrospective pilot matched cohort study

Postoperative pain after robot-assisted laparoscopic prostatectomy (RALP) involves the dermatomes from T9 to L1, exceeding the coverage of the conventional lateral transversus abdominis plane (TAP) block, prompting the use of supplementary upper abdominal blocks.We compared two strategies in patients undergoing RALP: lateral TAP plus subcostal TAP (Group S) and lateral TAP plus a modified thoracoabdominal nerve block through the perichondrial approach (M-TAPA; Group M).In this single-center retrospective pilot-matched cohort study, adult patients who received either block combination at the end of surgery between February 2023 and July 2024 were reviewed.Group M patients were matched 1:1 with Group S patients according to sex, age, body mass index, and ASA physical status.Pain scores were assessed using a numeric rating scale (NRS), and rescue analgesia use, recovery outcomes, and adverse events were analyzed.Seven matched pairs were included in the study.NRS at PACU arrival did not differ between the groups (5 [5-6] vs. 4 [4-5.5];p=0.264), but rescue analgesia within 48 h was required in all seven patients in Group M and none in Group S (p<0.001).NRS scores converged at 1 h postoperatively but were significantly higher in Group M at 24 h (6 vs. 2; p=0.010).The rescue dose count and length of hospital stay were also greater in Group M. No block-related adverse events occurred.These exploratory pilot findings suggest potential differences in the postoperative analgesic profiles between the two block strategies; however, larger prospective studies are required before definitive conclusions can be drawn.