Percutaneous ilioinguinal-iliohypogastric nerve block or step-by-step local infiltration anesthesia for inguinal hernia repair: what cadaveric dissection says?

PURPOSE The repair of groin hernias with local anesthesia has gained popularity. Two main methods have been described for local anesthesia. This study was aimed at comparing percutaneous truncular ilioinguinal-iliohypogastric block and step-by-step infiltration technique by using cadaver dissections. METHODS The study was performed on an adult male cadaver by using blue dye injection. A percutaneous nerve block simulation was done on right side and the dye was given in between the internal oblique and transversus muscles. On the left side, a skin incision was deepened and the dye was injected under the external oblique aponeurosis. Following the injections, stained areas were investigated superficially and within the deeper tissues with dissection. RESULTS There was a complete superficial staining covering the iliohypogastric and ilioinguinal nerves in the inguinal floor at both sides. On the right side, intraabdominal observation showed a wide and intense peritoneal staining, while almost no staining was seen on the left side. Preperitoneal dissection displayed a massive staining including testicular vascular pedicule and vas deferens on the right side. The dye solution also infiltrated the area of the femoral nerve prominently. On the contrary, a very limited staining was seen on the left. CONCLUSION It may not always be easy to keep the percutaneous block within optimum anatomical limits without causing adverse events. A step-by-step infiltration technique under direct surgical vision seems to be safer than percutaneous inguinal block for patients undergoing inguinal hernia repair.