QS119 - A Comparative Analysis of Laparoscopic and Ultrasound-Guided TAP Blocks in Minimally Invasive Colorectal Surgery in a Community Hospital

Purpose/Background: Transversus abdominis plane (TAP) block has recently emerged as an adjunct to post-operative pain management in abdominal surgery - reducing post-operative pain, narcotic use, post-operative nausea and vomiting, and increasing patient satisfaction. While the benefit of TAP blocks has been reproduced in many minimally invasive surgeries, it is unclear whether the ideal way for administration is via ultrasound-guided injection (US TAP) or under direct laparoscopic guidance (LAP TAP). The aim of this study was to assess whether there was a significant difference in post-operative analgesia between US TAP and LAP TAP. Our hypothesis is that the LAP TAP will be superior to the US TAP in the colorectal patient population.

Methods/Interventions: This was a single-institution retrospective chart review study. Data was obtained from patient charts of those who had undergone minimally invasive colorectal surgery between July 2020 and September 2022. In total, 104 patients were selected for final analysis that met inclusion criteria. Data were collected on requirement for post-operative IV narcotic rescue medication use, morphine equivalent dose (MED) of opioid consumption, average pain scores over the first 24 hours post-operatively, hospital length of stay (LOS), operative procedure length, and patient demographics including age, sex, and BMI.

Results/Outcomes: In the analysis of 104 patients, 20 patients had undergone LAP TAP while 84 had undergone US TAP. The US TAP group was more likely to receive narcotic rescue versus LAP TAP (82.1% vs. 55.0% respectively, p < 0.05). The odds of requiring narcotic rescue were 3.7 times higher for the US TAP group compared to the LAP TAP group (OR 3.7, 95% CI 1.14 - 11.98). The mean pain score for the LAP TAP was 3.22, while for the US TAP it was 4.39 (p < 0.05, 95% CI -2.19 to -0.17). No difference was found in MED of narcotics used or hospital LOS between the two groups. For the subgroup analysis of obese patients (BMI > 30), pairwise comparison demonstrated that the odds of requiring a narcotic rescue were 12.5 times greater (2.526 log odds ratio, p = 0.0063) in the US TAP group compared with the LAP TAP group. No difference in post-operative MED, pain scores, or hospital LOS were found when comparing US TAP versus LAP TAP in obese patients.

Conclusion/Discussion: LAP TAP significantly reduced the requirement for post-operative rescue IV narcotic pain medication and post-operative pain scores were lower when compared with US TAP. This difference was even more pronounced within the subgroup analysis of obese patients, suggesting that LAP TAP is the preferred strategy in patients with an increased abdominal wall depth. The results of our study suggest that LAP TAP is superior to US TAP with regards to post-operative analgesia in the colon and rectal surgery population, especially the obese population.