Transversus abdominis plane block for anterior lumbar interbody fusion: a randomized controlled trial

BACKGROUND CONTEXT Anterior lumbar interbody fusion (ALIF) is a lumbar arthrodesis technique via an anterior approach that is less invasive than the posterior approaches. However, it is associated with specific pain in the abdominal wall. PURPOSE The objective of this study was to determine whether performing a bilateral ultrasound-guided Transversus abdominis plane (TAP) block allows a reduction in morphine consumption in the first 24 hours after surgery. STUDY DESIGN This study is a prospective single-center, randomized, double-blind study. PATIENT SAMPLE Patients undergoing ALIF surgery were included and randomized into two groups. Both groups received a TAP block performed at the end of surgery with either ropivacaine or placebo. OUTCOME MEASURES The primary outcome measure was morphine consumption in the first 24 hours. The main secondary outcomes were immediate postoperative pain and opioid-related side effects. METHODS Intra- and postoperative anesthesia and analgesia protocols where standardized. A bilateral ultrasound-guided TAP block was performed with 75 mg (in 15 mL) of ropivacaine per side or isotonic saline serum depending on their assignment group. RESULTS Forty-two patients were included in the study (21 per group). Morphine consumption at 24 hours (28 mg [18–35] in the ropivacaine group versus 25 mg [19–37] in the placebo group [p=.503]) were not significantly different between the two groups. CONCLUSION TAP block with ropivacaine or placebo provided a similar postoperative analgesia when associated with a multimodal analgesia protocol for ALIF.