Comparison of the effectiveness of ultrasound-guided Transversus Abdominis Plane and Transversalis Fascia Plane blocks for postoperative analgesia in repeated cesarean section cases: A prospective observational study

Aim: The aim of this study is to compare the effects of the Transversus Abdominis Plane (TAP) block and the Transversalis Fascia Plane (TFP) block, applied to reduce postoperative pain in pregnant women undergoing repeat cesarean section under spinal anesthesia, on pain scores at rest and during movement, the time to first mobilization, and the amount of analgesic consumption. Materials and Methods: A total of 90 patients aged between 20 and 45 years, with ASA physical status scores of 1 or 2, who underwent repeat cesarean section and received TAP or TFP block for postoperative analgesia, were evaluated in the postoperative period. The patients were divided into two groups: those who received the Transversalis Fascia Plane block (Group I) and those who received the Transversus Abdominis Plane block (Group II). Pain scores were assessed at 0, 3, 6, 12, and 24 hours postoperatively using the Visual Analog Scale (VAS), both at rest and during movement. The time to first mobilization was also recorded. If necessary, additional analgesic agents such as paracetamol, diclofenac sodium, and tramadol were administered in addition to the blocks. The total amount of analgesics used within the first 24 hours postoperatively was documented. Furthermore, complications possibly related to opioid use, such as nausea, vomiting, and itching, were noted during the 24-hour period. Data obtained from the study were analyzed using the IBM SPSS 25.0 software package (SPSS Inc., Chicago, IL, USA). Results: In patients who received the Transversalis Fascia Plane block (Group I), pain scores at rest and during movement at the 3rd, 6th, 12th, and 24th hours were found to be statistically significantly lower compared to those who received the Transversus Abdominis Plane block (Group II). Additionally, when comparing the time to first postoperative mobilization, patients in Group I were mobilized significantly earlier than those in Group II (p=<0.001). When comparing the amount of analgesic use between the groups, it was observed that patients in Group II used 4 significantly more paracetamol and diclofenac sodium than those in Group I (p=<0.001). No significant difference was found between Group I and Group II in terms of tramadol usage (p=0.101). Complications potentially related to opioid use were observed at similar rates in both groups. Conclusion: Transversalis Fascia Plane block was found to be more effective than the Transversus Abdominis Plane block in controlling postoperative pain, with lower pain scores observed. In terms of the time to first mobilization, the Transversalis Fascia Plane block also allowed for earlier mobilization. While no significant difference was observed in opioid consumption between the groups, the use of paracetamol and diclofenac sodium was higher in the group that received the Transversus Abdominis Plane block. These findings suggest that the Transversalis Fascia Plane block is superior to the Transversus Abdominis Plane block for postoperative pain management following cesarean section. Keywords: Transversalis Fascia Plane block, Transversus Abdominis Plane block, opioid consumption, repeat cesarean section, first mobilization time.