Neurotoxicity of Anesthetic Agents and the Developing Brain in Rodents and Primates: The Time Has Come to Focus on Human Beings

In Reply: We thank you for Dr. Mohammadhosseini’s comments to our article on predictive risk factors for persistent postherniotomy pain. We will emphasize that the main purpose of the study was to identify relevant preoperative risk factors together with detailed neurophysiological data from open versus laparoscopic groin hernia surgery. We used high ligation and cutting of the hernia sac in indirect hernia, which was the case in 60% of patients. We believe that the literature on the role of sack ligation is not conclusive and at least not quantitatively important for persistent pain. Regarding type of mesh, this was reported in our article, and we agree that the heavyweight mesh used in the Lichtenstein repair may— although the literature again is not conclusive—result in more postoperative discomfort ant potentially persistent pain problems. However, this again does not invalidate our study, where the methodology otherwise is well explained. The point on nerve identification is well taken—although again the literature is not finally conclusive. The ilioinguinal and iliohypogastric nerves were identified in about 95% of cases, but in only about 20% could the genitofemoral nerve be identified; 2.2% of nerves were cut on purpose to allow sufficient position in suturing of the mesh. We do not agree that the quoted study by Caliskan et al. is conclusive on prophylactic neurectomy compared with other studies in the literature, also because the study included only 54 patients, which in our opinion is insufficient to provide useful answers on persistent pain problems. Since our large two-center study was planned, a better understanding of some surgical risk factors has become available, such as those raised by Dr. Mohammadhosseini. However, although such modifications of surgical technique may alter the risk of persistent pain, we believe that our well described study, including preoperative characterization as well as 6 months follow-up with neurophysiological assessment, provides unique information and better understanding of the mechanisms of persistent postherniotomy pain and the potential to reduce this burden.