ABSTRACT
Objective: To investigate the application of cochlear nerve action potential (CNAP) monitoring in the resection of vestibular schwannoma, especially evaluating its significance for hearing preservation. Methods: From April 2018 to December 2021, 54 patients with vestibular schwannoma who underwent resection via retrosigmoid approach were collected in Chinese PLA General Hospital. Before surgery, all patients had effective hearing (AAO-HNS grade C or above). Brainstem auditory evoked potential (BAEP) combined with CNAP monitoring was performed during surgery. The CNAP monitoring was combined with continuous monitoring and cochlear nerve mapping. And patients were divided into hearing preservation group and non-preserved group according to postoperative AAO-HNS grade. SPSS 23.0 software was used to analyze the differences of CNAP and BEAP parameters between the two groups. Results: A total of 54 patients completed intraoperative monitoring and data collection, including 25 males (46.3%) and 29 females (53.7%), aged 27-71 years with an average age of 46.2 years. The maximum tumor diameter were (18.1±5.9) mm (range 10-34 mm). All tumors were totally removed with preserved facial nerve function (House-Brackmann grade I-II). The hearing preservation rate of 54 patients was 51.9% (28/54). During surgery, the V wave extraction rate of BAEP waveform was 85.2% (46/54) before tumor resection, 71.4% (20/28) in the hearing preservation group after tumor resection, and disappeared in the hearing preservation group (0/26). CNAP waveform was elicited in 54 patients during operation. Differences were found in the distribution of CNAP waveforms after tumor resection. The waveforms of the hearing-preserving group were triphasic and biphasic, while those in the non-preserving group were low-level and positive. For hearing preservation group, the amplitude of N1 wave after tumor resection was significantly higher than that before tumor resection[14.45(7.54, 33.85)μV vs 9.13(4.88, 23.35)μV, P=0.022]; However, for the non-preserved group, the amplitude of N1 wave after tumor resection was significantly lower than that before tumor resection [3.07(1.96, 4.60)μV vs 6.55(4.54, 9.71)μV, P=0.007]; After tumor resection, the amplitude was significantly higher than that of the unreserved group [14.45(7.54, 33.85)μV vs 3.07(1.96, 4.60)μV, P<0.001]. Conclusions: BAEP combined with CNAP monitoring is conducive to intraoperative hearing protection, and the application of cochlear nerve mapping can prompt the surgeon to avoid nerve injury. The waveform and N1 amplitude of CNAP after tumor resection have a certain value in predicting postoperative hearing preservation status.
Subject(s)
Female , Male , Humans , Middle Aged , Neuroma, Acoustic/surgery , Action Potentials , Evoked Potentials, Auditory, Brain Stem , Cochlea , Cochlear NerveABSTRACT
Objective Probe into different method safe and effective fixation method,clinical result and cliniical to indications of different treatments in intertrochanter fracture of femur in the old elderly.Methods Adopting the femur near end dissecting type to lock the stencil plate fixation 14 of 58 cases of old intertrochanter fracture of femur separately.the hip screw of motive force(DHS) fixation was used in 24,femur near end stencil plate fixation in 20,and the blood loss,operation time,ossicle split off situation and fracture heal time were compared among the three groups.Sanders grade results and complications were followed up.Results Postoperative follow up Was done in all patients,from 8 months to 3 years,averaged 1.5 years.three groups of skill type fine rate of the three groups being 92.9%,92%,90%respectively.Conclusions Different methods showed good clinical results in treating the old intertrochanter fracture of femur,each having its indications.Operation should be done should follow based on fracture type,age,physique factors and patient's osteoporosis intensity,choosing the best healing solution by characteristics of intermal flxation while each combining.The hook board(ALHP)is suitable for old patients with serious osteoporosis,DHS for Evans Ⅰ,Ⅱ types and some Evans Ⅲ type,and femur near end dissecting type stencil plate for Ⅳ and Ⅴ types fractures.