Results
During the study period, 129 patients met the inclusion criteria. Of these, five patients declined to participate, and additional four patients were excluded due to technical reasons (none of the investigating surgeons was available). After enrollment, one patient was found to have malignancy during the operation. Ultimately, 119 patients (group 1- 30, group 2- 30, group 3- 29, group 4- 30) completed full pain assessment (Figure 1). All patients returned for a follow up visit. No early / late complications or adverse effects were registered for the study population. No malignancy was detected on final pathological examination (for the patient who completed enrollment and were included in the final analysis).
We did not detect any differences between the study groups and the patient and surgery characteristics (Table 1). Also, there was no difference in the frequency of major vs. minor surgeries between the study groups (P-value=0.34, Tables S1 A and B).
No significant associations were found between the study groups and the discrete and total VAS scores in 3, 8 and 24 hours after surgery, in either univariate and multivariate analyses (Table 2, Figure 2, and Table S2).
No significant association was found between the study groups and the MME given during recovery, and the Analgesic index (Table S2). Only 6 patients were treated with opioids 3 hours post-surgery (there was no difference between the groups). None needed such treatment at and 8 and 24 hours post-surgery. Furthermore, we did not detect differences in the risk for pain that required analgesic treatment in both univariate and multivariate analyses.
When comparing patients who were treated with and without subcutaneous anesthesia and patients with and without intra-peritoneal anesthesia, we did not detect differences in both pain assessment and analgesic prescription outcomes (Table S3).