Correction to: Safety of the "Saxophone®" electrode in parotid surgery for continuous intraoperative neuromonitoring of the facial nerve: results of a pro- and retrospective cohort study.

In the original publication of the article, first name and last names of all authors were swapped.

Safety of the "Saxophone®" electrode in parotid surgery for continuous intraoperative neuromonitoring of the facial nerve: results of a pro- and retrospective cohort study.

PURPOSE: Early facial nerve palsy (eFNP) is the most frequent complication of the parotidectomy. Intraoperative neuromonitoring (IONM) in parotid surgery, which aims at reducing eFNP, has not evolved any further than the mere differentiation between the nerve and the surrounding tissue. Continuous IONM (cIONM), used in thyroid and posterior fossa surgery, has developed over the past years and has proved beneficial in reducing the rate of paresis in cases where a pattern of impending nerve injury is identified. In this study, we aim to demonstrate the safety of using the stimulating electrode (Saxophone®) for cIONM in parotid surgery. METHODS: From 2016 to 2018, 40 patients who were referred for primary parotidectomy under cIONM according to our study protocol (registered at the German Clinical Trials Register, DRKS-ID: DRKS00011051, http://www.drks.de; http://apps.who.int/trialsearch) were included in this study. All patients with a normal preoperative facial nerve function [House-Brackman (HB)-Index 1] underwent surgery using continuous facial nerve stimulation with the Saxophone® electrode (system AVALANCHE XT, Dr. Langer Medical, Waldkirch, Germany). A control group which underwent parotidectomies with only intermittent IONM was recruited from our records. RESULTS: Half of the patients in our study group suffered from eFNP. All except one regained normal facial nerve function within 6 months of surgery. There was no significant difference regarding eFNP when compared to the control group without cIONM (p = 0.11). No statistically significant correlation between the stimulation threshold (p = 0.74) or the duration of nerve stimulation and eFNP was found (p = 0.51). CONCLUSION: We have demonstrated the safety of using the Saxophone®-electrode for cIONM of the facial nerve in parotid surgery. Future development of this method could enable the recognition of impending nerve injury and thus reduce eFNP.

Antero- vs. retrograde nerve dissection in parotidectomy: a systematic review and meta-analysis.

INTRODUCTION: The retrograde approach (RP) to nerve identification is a method seldom used in parotid surgery. A systematic review comparing this method to the standard anterograde approach (AP) with respect to facial nerve palsy (FNP) does not currently exist. METHODS: In a meta-analysis according to the PRISMA statement, eight publications, including one randomized controlled trial, were selected. The primary aim was to compare the temporary and permanent FNP resulting from the two dissection methods. Facial nerve function was graded according to the House-Brackmann Scale. The secondary goal was a comparison of the cut-suture times (CST), the volume of healthy tissue (VHT) dissected, the rates of postoperative hematoma (PH), and postoperative infection (PI). RESULTS: Temporary FNP was noted in 18.2% in the RP group as well as in 34.4% in the AP group. Permanent FNP occurred in 0.9% RPs and 2.4% APs. According to the mixed-effect logistic regression model, there was no significant difference between the two groups in the pooled odds ratio (OR) for either temporary [OR 2.64, 95% confidence interval (CI) 0.97-7.21] or permanent FNP (OR 4.31, 95% CI 0.44-42.28). The CST was significantly shorter in the RP group (p = 0.005), with a significantly smaller VHT dissected (p < 0.0001). There were no differences regarding PH and PI. CONCLUSION: The RP is a safe procedure with no significant difference in FNP rates when compared to the AP and, considering the shorter CST and the lesser VHT resected in the RP, it is superior to the AP. Surgeons engaged in parotidectomy should be familiar with both methods of dissection.

Does Microscope Assistance in Cold Steel Tonsillectomy Reduce the Risk of Postoperative Hemorrhage? Results of a Prospective Cohort Study.

BACKGROUND: Posttonsillectomy hemorrhage (PTH) is the most feared complication. Dissection near the tonsillar capsule under microscopic view (TEmic) could be assumed to decrease PTH compared to traditional tonsillectomy (TEtrad). METHODS: In this study, patients were evaluated with respect to the need for surgical control (R/N: return/no return to theater (RTT): the day of surgery [0] or thereafter [1]). The findings at resection site and pain were measured. RESULTS: 869 patients were included (183 TEmic; 686 TEtrad). PTH requiring RTT was not seen in the TEmic group on the day of surgery (R0) while PTH requiring RTT subsequently (R1) was seen in 1.1% of the cases. In the TEmic group, hemorrhages without a need for surgical control were observed in 0.6% (N0) and 3.4% (N1), respectively. The corresponding rates for TEtrad were as follows: R0, 0.3%; R1, 1.7%; N0, 0.6%; and N1, 3.6% (p > 0.05). Postoperative edema and local infection at resection site were proven to be predictive of PTH (p = 0.007). CONCLUSION: Microscope assistance in tonsillectomy did not statistically have an influence on the PTH even though there was a trend towards lower PTH rate in the TEmic group. Benefit for TEmic was observed in high-volume and long experienced surgeons.

Hyperplasia and the degree and activity of inflammation in chronic recurrent tonsillitis: a histopathological study.

Postoperative haemorrhage following tonsillectomy occurs in 5.98% of all cases with up to 10 deaths reported annually in Germany. When comparing tonsillectomy (TE) and tonsillotomy (TT), the same long-term frequency of ENT infections is displayed in children and young adults. However, taking postoperative haemorrhaging into account, TT is more favourable. Chronic tonsillitis is one of the most common indications for TE in the adult population; however, a histopathological characterization may reveal objective criteria and provide a foundation for routinely performing TT in adults too. Three essential parameters hyperplasia (HP), grade of inflammation (GOI) and activity of inflammation (AOI), which are responsible for, and associated with a clinically relevant disease were histopathologically examined in the tonsils of 100 adult patients with chronic recurrent tonsillitis. The parameters were analysed and compared separately in the pharyngeal and basal parts of the tonsils as well as in three sections (upper and lower pole of the tonsil, middle part) as this may influence the indication for TT. The comparison of the basal and pharyngeal portions displayed a significant difference in the GOI and the HP in all three sections: grade 2 HP as well as GOI were more commonly found in the basal than pharyngeal portions (p > 0.001). AOI (grade 2) displayed the same properties in the middle section (p < 0.002), but did not reach statistical significance in the cranial and caudal sections (p = 0.107 and p = 0.186). An overabundance of grade 1 GOI, AOI, and HP was seen in the pharyngeal sections. The results show that two out of three relevant parameters that demonstrate histopathological changes in recurrent inflamed tonsils have a significantly stronger presence in the basal section of the tonsil as opposed to the pharyngeal section. The processes initiated by inflammation next to the surface responsible for a clinically relevant recurrent tonsillitis seem to cause stronger reactions in the deep follicular portion of the tonsils.

Transplantation of human neural precursor cells in the 6-OHDA lesioned rats: effect of immunosuppression with cyclosporine A.

Neural precursor cells (NPC) may provide a source for restaurative therapy. We wanted to study the immunogenic potential of human NPC. We transplanted human NPCs with or without cyclosporine A (10 mg/kg) expanded in serum-free conditions into the striatum of rats unilaterally lesioned with 6-hydroxydopamine. Four months after transplantation, there was significant improvement of amphetamine-induced rotational behavior 9 non-immunosuppressed (13.1+/-4.9 pre vs 8.5+/-4.0 after grafting) but nor for 11 animals immunosuppressed with CyA (12.3+/-1.7 vs 11.3+/-2.8). The number of TH-IR cells was comparable in both groups (1,580+/-700 vs 1,274+/-295). All grafted animals only showed mild activation of astrocytes and macrophages within the graft. There was no evidence for tumor formation. Immunosuppression of rats, xenotransplanted with human NPC did not improve graft survival or function.