Background and objectives: In this study, we compare paravertebral block (PVB) of the T10 and L1 segments and multiple-segment PVB for anesthesia and analgesia in inguinal hernia surgeries.
Methods: Anatomic study was performed on 3 cadavers. A 15-mL methylene blue solution was injected at the T10 level and then an additional 5-mL dye injection at L1 level. Fifty patients were included in the study. Patients in group 1 (n = 25) underwent PVB of 2 segments at the T10 and L1 vertebrae levels on the same side as the hernia, whereas patients in group 2 (n = 25) underwent PVB through 4 segments at T10, T11, T12, and L1 on the same side as the hernia. Perioperative propofol/remifentanil consumption, surgery start time, time to perform the block, duration of sensory block, postoperative visual analog scale scores, and complications were evaluated.
Results: Any passage down to the T12 level was not observed after injection at the T10 level and also only after additional 5-mL dye injection at the L1 level; the genitofemoral, ilioinguinal, iliohypogastric, and lateral femoral cutaneous nerves were stained with dye in cadavers. The times for block application were 5 mins (SD, 1 min) in group 1 and 16 mins (SD, 4 mins) in group 2 (P < 0.001). The surgery start time was 25 mins (SD, 3 mins) in group 1 and 27 mins (SD, 6 mins) in group 2 (P = 0.234). In both groups, propofol and remifentanil were used in similar quantities during the perioperative period. Use of paracetamol tablets was similar in both groups (P > 0.05). Whereas none of the patients in group 1 displayed motor block or contralateral spread, 2 patients in group 2 displayed contralateral spread, and motor block was observed in 1 patient. Twenty-three patients (92%) in group 1 and 24 patients (96%) in group 2 were satisfied with the method (P > 0.05).
Conclusion: Two-segment PVB can be an alternative to 4-segment PVB in inguinal hernia surgeries. Decreasing the number of injections required in this technique may further increase patient comfort and decrease complications.