Novel use of laparoscopic-guided TAP block in total laparoscopic hysterectomy.

Background: Transverse abdominis plane (TAP) block is a peripheral nerve block designed to anaesthetise the nerves supplying the anterolateral abdominal wall (T6 to L1). We introduced laparoscopic TAP block at Ninewells Hospital in 2014 and present a retrospective study assessing its efficacy. To our knowledge, there is limited study done on laparoscopic-guided TAP block whilst there are abundant literatures available on ultrasound-guided TAP block.

Aims: To evaluate the efficacy of laparoscopic-guided TAP block as postoperative analgesia following total laparoscopic hysterectomy (TLH).

Methodology: A retrospective study was done between November 2014 to October 2016 (24 months) comparing patients who had TLH with TAP block (Group 1; n = 45) and patients who had TLH without TAP block (Group 2; n = 31) in our gynaecology unit. Patients were identified from theatre database. Data was collected from clinical portal and medical notes. The data included demographic information, BMI, METS score, intra-operative opiates use, post-operative pain scores, opiate requirements and use of patient-controlled analgesia (PCA), total dose of opiates used and day of discharge. The outcomes were analysed using means, odds ratios (OR), Mann-Whitney U-test and Fisher's exact or Chi-square test with 95% confidence interval (CI).

Results: Patients in Group 1 were older (mean age of 64.4, range 38-87) when compared to Group 2 (mean age of 49.3, range 37-81). Group 1 and 2 had comparable mean BMI (30.34 vs. 30.02) and METS score (6.77 vs. 7.76). Mean post-operative pain scores were lower in Group 1 within 4 hours, in periods of 4-12 hours, 12-24 hours and 24-48 hours post-op. Smaller proportion of patients in Group 1 required opiates post-operatively in all periods as compared to Group 2. This was statistically significant in the periods of 12-24 hours post-op (OR 0.31, 95% CI 0.11-0.82; p = .01). PCA use was significantly lower in Group 1 (OR 0.02, 95% CI 0.0014-0.46; p = .01). Group 1 had lower mean total dose of opiates used (27.182 mg, range 0-102 mg) than Group 2 (59.452 mg, range 0-240 mg), which was statistically significant (p < .0001). Average post-op hospital stay was 1.3 and 1.8 days in Group 1 and 2, respectively.

Conclusion: Laparoscopic-guided TAP block delivered as post-operative analgesia following TLH results in reduced opiate requirement at post-operative period 12-24 hours, reduced PCA use and lower total dose of opiates used.