Surgeon-delivered laparoscopic transversus abdominis plane blocks are non-inferior to anesthesia-delivered ultrasound-guided transversus abdominis plane blocks: a blinded, randomized non-inferiority trial

Abstract

Background: The transversus abdominis plane (TAP) block is an important non-narcotic adjunct for post-operative pain control in abdominal surgery. Surgeons can use laparoscopic guidance for TAP block placement (LTAP), however, direct comparisons to conventional ultrasound-guided TAP (UTAPs) have been lacking. The aim of this study is to determine if surgeon placed LTAPs were non-inferior to anesthesia placed UTAPs for post-operative pain control in laparoscopic colorectal surgery.

Methods: This was a prospective, randomized, patient and observer blinded parallel-arm non-inferiority trial conducted at a single tertiary academic center between 2016 and 2018 on adult patients undergoing laparoscopic colorectal surgery. Narcotic consumption and pain scores were compared for LTAP vs. UTAP for 48 h post-operatively.

Results: 60 patients completed the trial (31 UTAP, 29 LTAP) of which 25 patients were female (15 UTAP, 10 LTAP) and the mean ages (SD) were 60.0 (13.6) and 61.5 (14.3) in the UTAP and LTAP groups, respectively. There was no significant difference in post-operative narcotic consumption between UTAP and LTAP at the time of PACU discharge (median [IQR] milligrams of morphine, 1.8 [0-4.5] UTAP vs. 0 [0-8.7] LTAP P = .32), 6 h post-operatively (5.4 [1.8-17.1] UTAP vs. 3.6 [0-12.6] LTAP P = .28), at 12 h post-operatively (9.0 [3.6-29.4] UTAP vs. 7.2 [0.9-22.5] LTAP P = .51), at 24 h post-operatively (9.0 [3.6-29.4] UTAP vs. 7.2 [0.9-22.5] LTAP P = .63), and 48 h post-operatively (39.9 [7.5-70.2] UTAP vs. 22.2 [7.5-63.8] LTAP P = .41). Patient-reported pain scores as well as pre-, intra-, and post-operative course were similar between groups. Non-inferiority criteria were met at all post-op time points up to and including 24 h but not at 48 h.

Conclusions: Surgeon-delivered LTAPs are safe, effective, and non-inferior to anesthesia-administered UTAPs in the immediate post-operative period.

Trial registry: The trial was registered at clinicaltrials.gov Identifier NCT03577912.

Keywords: Enhanced recovery after surgery; Laparoscopy; Post-operative pain control; Transversus abdominis plane (TAP) block.

Conflict of interest statement

Disclosures

Dr. Wong reports no conflict of interest.

Dr. Curran reports personal fees from KCI Inc, outside the scope of the submitted work.

Dr. Poylin reports no conflict of interest.

Dr. Cataldo reports no conflict of interest.

Figures

FIGURE 1.. CONSORT flow diagram of patients in trial.

Abbreviations: UTAP (Ultrasound guided transversus abdominis block) LTAP (laparoscopic guided transversus abdominis block)

FIGURE 2.. Surgeon delivered laparoscopically guided TAP block.

(A) Laparoscopic view of abdominal wall with circle highlighting initial bulge of injection within the TAP plane. Laparoscope is used to ensure peritoneum is not entered with needle. (B) Laparoscopic view of anesthetic spreading along TAP plane following injection.

FIGURE 3.. Post-operative narcotic consumption.

(A) No significant differences in opiate requirement between anesthesia administered ultrasound guided TAP block (UTAP) and surgeon administered laparoscopic TAP block (LTAP) Bars represent mean opiate consumption ± SD. (B) Graphic representation of 95% CIs of difference of means of opiate requirements in relation to 15mg non-inferiority margin. Numbers indicate bounds of 95% CI. * signifies met non-inferiority criteria at indicated time point. Abbreviations: PACU (Post-anesthesia care unit) mg (milligrams)

FIGURE 4.. Post-operative pain scores.

No differences in patient reported pain scores at rest (a) or in motion (b) between UTAP and LTAP groups. Bars represent mean scores ± SD. * = p