Preoperative vs Postoperative Transverse Abdominal Plane Blocks for Renal Surgery: A Systematic Review and Network Meta-Analysis
Andrew S. Lee BA1, Alejandro Hallo Carrasco MD1, Anthony Cusumano BS, MS1, Shreya Desai, BS1, Kalyna Leshchuk BS2, Nivetha Srinivasan MD1, Aditi Master MD1, Rakesh Sondekoppam MBBS3, Jean D. Eloy MD1, Hari Kalagara MBBS, MD4, Alexander Pekurovsky MD1, Michael A. Akerman MD1
1Rutgers New Jersey Medical School, 2Rowan-Virtua School of Osteopathic Medicine, 3Stanford University, 4 Mayo Clinic - Florida
Introduction
•The transversus abdominis plane (TAP) block is an ultrasound-guided technique that provides abdominal wall analgesia by depositing local anesthetic between the internal oblique and transversus abdominis muscles.
In patients with renal dysfunction or renal allografts, concerns about nephrotoxicity often limit analgesic options and increase reliance on opioids. TAP blocks reduce postoperative pain and opioid use, but the optimal timing of administration remains unclear.
•We performed a network meta-analysis to evaluate outcomes according to the timing of TAP block administration.
Materials and Methods
•This study was reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines.
•Two independent reviewers screened studies from MEDLINE, Embase, CENTRAL, and ClinicalTrials.gov. Randomized controlled trials involving adult patients undergoing donor nephrectomy or renal transplantation were included.
•The primary outcomes were 24-hour postoperative opioid consumption (MME) and VAS pain scores at 24 hours.
•Studies were categorized by preoperative versus postoperative TAP block administration, and indirect comparisons were performed.
Results
•Seven studies met the inclusion criteria (5 preoperative TAP, 2 postoperative TAP) (Figure 1). Statistical heterogeneity was substantial across analyses (I² > 75%).
•For 24-hour opioid consumption, preoperative TAP block did not significantly reduce opioid use compared with control (MD −4.07 MME; 95% CI −10.05 to 1.91; p=0.181). In contrast, postoperative TAP block was associated with a significant reduction in opioid consumption (MD −14.66 MME; 95% CI −17.40 to −11.91; p < 0.001). Indirect comparison demonstrated lower opioid consumption with postoperative compared with preoperative TAP block (Figure 2).
•For VAS pain scores at 24 hours, postoperative TAP significantly reduced pain compared with control (MD −0.548; 95% CI −0.706 to −0.390; p < 0.001), whereas preoperative TAP showed no significant difference (MD −0.087; 95% CI −0.267 to 0.093; p = 0.342).
Discussion
•Possible explanations for the greater effectiveness of postoperative TAP blocks include intraoperative surgical manipulation dispersing local anesthetic administered preoperatively, reducing its duration of action.
•Postoperative blocks are performed closer to the time of pain assessment, which may enhance their apparent analgesic effect. Additionally, somatic incisional pain is often more clearly perceived after surgery, potentially increasing the observed benefit of postoperative administration.
Take Away Points
Postoperative TAP blocks were associated with lower 24-hour opioid consumption and pain scores compared with control, while preoperative TAP blocks did not show a significant benefit.
Timing of TAP block administration may influence analgesic effectiveness, suggesting postoperative placement may provide greater measurable benefit in renal surgery.
References
1.Iaquinandi, F., Laparoscopic vs. ultrasound-guided transversus abdominis plane (TAP) block in colorectal surgery: a systematic review and meta-analysis of randomized trials. Surgical endoscopy (2024)
2.Zarate Rodriguez, J., Preoperative transversus abdominis plane block decreases intraoperative opiate consumption during minimally invasive cholecystectomy. Surgical endoscopy, (2023)
3.Chang-Patel, E. J., The Effect of Transversus Abdominis Plane Block Timing on Milliequivalents of Opioid Use and Immediate Postoperative Pain Scores in Patients Undergoing Minimally Invasive Hysterectomy: A Retrospective Cohort Study. Journal of minimally invasive gynecology (2024)
4.Zárate Rodriguez, J. G., Preoperative transversus abdominis plane block decreases intraoperative opiate use during pancreatoduodenectomy. HPB : the official journal of the International Hepato Pancreato Biliary Association, (2022)
