三个半规管阻塞动物模型的建立

目的　旨在建立豚鼠单侧三个半规管阻塞的动物模型。方法　利用 2 0只豚鼠行单侧三个半规管阻塞 ,观察手术前后眼震电图、听性脑干反应 (auditorybrainstemresponses,ABR)、畸变产物耳声发射 (distortionproductotoacousticemissions,DPOAE)及形态学的变化 ,非手术耳作为对照。结果　豚鼠术后 1d出现自发性眼震 ,正弦摆动刺激单侧眼震反应消失 ,侧别与术侧一致 ,术后 30d左相与右相眼震反应对称。术前微量冰水灌注 ,两耳均能引出眼震 ,术后 30d做冰水实验结果为术耳未能引出眼震 ,非术耳出现正常的眼震反应。术后ABR阈值有轻度升高 ,DPOAE反应幅度无明显改变。 8只动物病理切片证实三个半规管完全阻塞而耳蜗Corti器和壶腹嵴结构正常。结论　表明三个半规管阻塞动物模型成功 ,提示三个半规管阻塞术可望成为治疗难治性外周性眩晕的安全有效、操作相对容易的手术方法。     

半规管阻塞技术的初步临床应用

目的初步探讨临床应用半规管阻塞技术治疗位置性眩晕与梅尼埃病的安全性与有效性。方法回顾性分析1994-2000年间半规管阻塞技术临床应用的资料,其中,后半规管位置性眩晕2例,水平半规管位置性眩晕1例,内淋巴囊阻塞术后5年复发的梅尼埃病1例,男1例,女3例,年龄39-58岁。梅尼埃病患者行三半规管阻塞及内淋巴乳突腔分流术,位置性眩晕患者行相应的半规管阻塞术。结果位置性眩晕患者术后随访1.5-7年,全部患者位置性眩晕得到解除,术后纯音测听、中耳功能分析、听觉脑干电反应测试、耳声发射等听觉功能检查结果显示耳蜗功能与术前完全一致,水平半规管阻塞的患者双耳冷热试验结果显示手术消除了水平半规管的功能,后半规管阻塞的患者双耳冷热试验结果显示手术后以水平半规管为代表的其它前庭末梢器官的功能得到良好的保存。内淋巴囊阻塞术后5年复发的梅尼埃病患者术后随访2年,眩晕得到完全控制。结论半规管阻塞技术可有效控制位置性眩晕与梅尼埃病患者的眩晕,半规管阻塞对患者耳蜗功能及所阻塞半规管以外的其它前庭末梢器官功能没有影响,半规管阻塞技术可望成为位置性眩晕和梅尼埃病安全、有效的治疗手段,符合现代外科学对手术微创的要求。     

半规管阻塞术

半规管阻塞术是在半规管骨管上开窗后,用骨蜡、骨屑、筋膜、生物胶或激光阻塞或阻断内淋巴流。目前应用最多的是后半规管阻塞术治疗良性位置性阵发性眩晕,其疗效已得到了肯定。在用后半规管阻塞术成功地治疗良性位置性阵发性眩晕后,有人进行了三半规管阻塞,旨在探索治疗梅尼埃病的方法。本文综述了良性位置性阵发性眩晕的特点、发病机制、半规管阻塞术的方法、与其它手术的比较、引起听力损失和保存听力的机制。     

半规管阻塞术治疗顽固性梅尼埃病的短期疗效分析

目的 观察半规管阻塞术治疗顽固性梅尼埃病的短期疗效,评价其有效性和安全性.方法 回顾性分析17例行半规管阻塞手术的梅尼埃病患者资料,均为确诊单侧梅尼埃病,行规范化药物保守治疗至少1年以上,眩晕仍反复发作者.全麻下经乳突进路行三个半规管阻塞术,术后随访6～13个月,平均10个月.术前及术后3个月采用纯音测听、冷热试验和前庭诱发的肌源性电位检查( vestibular evoked myogenic potential,VEMP)进行听力学和前庭功能评价.结果 17例梅尼埃病患者,术前按听力进行分期,Ⅱ期(平均听阈25～40 dBHL)2例,Ⅲ期(41～70 dBHL)15例.术后随访期内均无眩晕发作,眩晕控制率为100％ (17/17).同期行内淋巴囊减压术的25例梅尼埃病患者,眩晕控制率为72.0％( 18/25),半规管阻塞术的眩晕控制率高于内淋巴囊减压术(x2=3.87,P＜0.05).术后3个月12例患者纯音平均听阈与术前相比无明显变化,5例听阈提高,但均小于20 dBHL,听力下降率29.4％ (5/17).术后所有患者均出现短时间眩晕及平衡障碍,眩晕均在术后3d内消失,10例患者术后1～2周内恢复平衡功能,7例患者术后2个月内平衡障碍完全消失,平衡恢复时间平均12.6d.术后3个月复查,全部病例冷热试验均提示半规管功能丧失,VEMP检查示球囊功能无变化.所有患者均无面神经麻痹、脑脊液漏等并发症发生.结论 半规管阻塞术治疗顽固性梅尼埃病短期疗效确切,听力保留率高,不影响耳石器功能,无严重并发症,有望成为治疗存在中度以上听力损失的顽固性梅尼埃病患者安全有效的手术方法.     

豚鼠半规管阻塞术中听性脑干反应的变化

目的：观察正常豚鼠行三个半规管阻塞术中ABR反应阈值的动态变化。方法：健康白色纯种豚鼠10只，分别于术前、打开听泡、开放与阻塞各个半规管后测ABR阈值。结果：三个半规管阻塞结束后，ABR阈值平均升高6．82dB。各个半规管开窗前后ABR阈值上升较明显，而阻塞前后ABR阈值变化不明显。结论：半规管阻塞术中的听力下降是一个渐进的过程，引起听力下降的主要原因可能是外淋巴的流失，迷路受刺激并非造成听力下降的主要因素。     

半规管阻塞技术的初步临床应用

目的 初步探讨临床应用半规管阻塞技术治疗位置性眩晕与梅尼埃病的安全性与有效性。方法 回顾性分析1994～2000年间半规管阳塞技术临床应用的资料，其中，后半规管位置性眩晕2例，水平半规管位置性眩晕l例，内淋巴囊阻塞术后5年复发的梅尼埃病1例，男l例，女3例，年龄39～58岁。梅尼埃病患者行三半规管阻塞及内淋巴乳突腔分流术，位置性眩晕患者行相应的半规管阻塞术。结果 位置性眩晕患者术后随访1．5～7年，全部患者位置性眩晕得到解除，术后纯音测听、中耳功能分析、听觉脑干电反应测试、耳声发射等听觉功能检查结果显示耳蜗功能与术前完全一致，水平半规管阻塞的患者双耳冷热试验结果显示手术消除了水平半规管的功能，后半规管阻塞的患者双耳冷热试验结果显示手术后以水平半规管为代表的其它前庭末梢器官的功能得到良好的保存。内淋巴囊阻塞术后5年复发的梅尼埃病患者术后随访2年，眩晕得到完全控制。结论 半规管阻塞技术可有效控制位置性眩晕与梅尼埃病患者的眩晕，半规管阻塞对患者耳蜗功能及所阻塞半规管以外的其它前庭末梢器官功能没有影响，半规管阻塞技术可望成为位置性眩晕和梅尼埃病安全、有效的治疗手段，符合现代外科学对手术微创的要求。     

单侧半规管阻塞对豚鼠前庭内侧核谷氨酸变化的影响

目的　探讨单侧外半规管阻塞造成的急性眩晕动物模型,前庭内侧核谷氨酸神经递质的变化规律。方法  在行为学验证基础上,利用活体微透析技术结合高效液相 色谱（high performance liquid chromatography,HPLC）-荧光检测方法,研究清醒状态下豚鼠前庭内侧核谷氨酸水平的变化。结果　半规管阻塞术后第1天动物出现头偏、头震及强迫环形运动等表现,上述症状于术后第4天逐渐消失。术后第1天实验组豚鼠前庭内侧核谷氨酸浓度较对照组显著提高,差异有统计学意义（t =7.4637,P <0.001）。术后第4天实验组豚鼠前庭内侧核谷氨酸浓度降低,与基线水平相比无显著差异（t =0.2447,P >0.05）。结论　豚鼠前庭内侧核谷氨酸水平显著性升高,可能与单侧半规管阻塞造成动物急性眩晕有关。     

同时性后半规管与水平半规管性良性位置性眩晕

目的：探讨同时性后半规管与水平半规管性良性位置性眩晕（混合性良性位置性眩晕）的诊治方法。方法：联合应用Epley手法和Barbecue翻滚法对4例患者进行治疗，两次治疗间隔1d。结果：4例患者眩晕症状完全消失，随访至今无复发。结论：混合性良性位置性眩晕兼有后半规管与水平半规管性良性位置性眩晕的临床表现，联合采用Epley手法和Barbecue翻滚法治疗该病是可行的。     

上半规管裂综合征经乳突径路手术治疗一例

目的 探讨上半规管裂综合征经乳突径路手术治疗的方法.方法 回顾性分析四川大学华西医院耳鼻咽喉头颈外科1例经乳突径路行上半规管填塞术的上半规管裂综合征患者的临床资料.结果 患者以听觉过敏为主诉,术前听力学及影像学检查符合上半规管裂综合征的特征.经乳突径路行上半规管填塞法手术治疗后,症状明显缓解.术后随访10个月,听力学检查恢复正常,听觉过敏基本消失.结论 上半规管裂综合征的手术治疗,相较于常规的经中颅窝径路,经乳突径路的上半规管裂手术治疗方法更简单、安全、省时,且疗效确切.     

半规管手术的基础与临床

近年来 ,由于基础研究的不断深入 ,人们对内耳解剖和生理的认识不断提高 ,临床上应用半规管手术治疗内耳疾病的范围也不断扩大。本文就半规管手术的基础研究和临床应用情况作一简介。1　半规管手术的实验依据Ｈａｒａ等 (1 993 )报道 ,在迷路外淋巴间隙中存在迷路界膜 (ｍｅｍｂｒａｎｅｌｉｍｉｔａｕｓ) ,界膜将迷路分隔为上部 (三个半规管和椭圆囊 )和下部 (球囊和耳蜗 )。它在迷路上、下部之间起着屏障作用 ,限制上、下部外淋巴液中的物质相互弥散。由于界膜的存在 ,我们可以在迷路上部给药而不影响下部 ,反之亦然。在膜性半规管周围的…     

三半规管阻塞与迷路切除术后前庭功能动态变化

目的 :比较豚鼠三半规管阻塞与迷路切除术后前庭功能代偿的异同。材料与方法 :将 15只健康豚鼠分为 2组 ,其中 8只豚鼠行右侧三半规管阻塞术 (triple semicircular canal occlusion,TCO) ,7只豚鼠行右侧迷路切除术(labyrinthectomy,L E) ,于术后一个月内观察豚鼠行为学及眼震电图 (ENG)的动态变化。结果 :发现术后第 1天两组均出现自发性眼震 ,正弦摆动刺激术侧时未引出诱发性眼震 ,头向右侧偏斜并沿地面垂直轴向术侧旋转 ;L E组却出现翻滚现象。术后第 3、5、10、15、30天正弦摆动眼震试验 ,两组豚鼠术侧眼震均随时间的推移逐渐恢复 ,TCO组于 15天左右向眼震基本恢复对称 ,而 L E组至术后 30天仅摆动幅度 12 0°、15 0°、180°左右向眼震基本对称 ,摆动幅度为 6 0°、90°双向眼震反应差异仍有显著性意义 (P <0 .0 5 ) ;另外 ,L E组有 3只豚鼠仍存在头偏。结论 :TCO组要比 L E组动物恢复快 ,建立代偿和失平衡时间短     

Transmastoid superior semicircular canal occlusion.

OBJECTIVE: The traditional surgical repair for superior semicircular canal dehiscence (SSCD) involves either canal plugging or resurfacing via the middle cranial fossa approach. We describe a novel transmastoid occlusion technique. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Three patients with symptomatic computed tomography-proven SSCD. INTERVENTION: Transmastoid superior semicircular canal occlusion using bone pate in 2 fenestrations, with 1 placed on either side of the dehiscence. MAIN OUTCOME MEASURES: Hearing and vestibular symptoms. RESULTS: Two patients were primary cases of SSCD, and a third patient had failed a previous middle fossa occlusion using fascia at an outside institution. In all 3 cases, the 2 sides of the superior semicircular canal adjacent to the dehiscence were occluded using bone pate, formed from a mix of bone dust and fibrin sealant. This allowed for a permanent bony partition to be achieved between the dehiscence and the remainder of the labyrinth. In all cases, hearing was either preserved or improved, and the procedure was successful in controlling vestibular symptoms. CONCLUSION: Transmastoid superior semicircular canal occlusion is a viable alternative to the customary middle fossa approach for superior canal dehiscence. Meticulous technique and the use of bone pate may help maximize auditory and vestibular results. Advantages of this technique include obviating a craniotomy, preclusion of temporal lobe retraction, familiarity of the approach for experienced otologists, and the ability to occlude the canal without manipulating the defect. The transmastoid approach for superior canal occlusion may not be possible when the dura is low hanging or when there is extensive cranial base dehiscence requiring reconstruction.     

Resection of the semicircular canal system with preserved hearing--an animal experiment study]

In a previous investigation we selectively resected the lateral semicircular canal of the rabbit, preserving the hearing in 67% of the animals. We now report an attempt to remove all three canals in one step with a microsurgical technique using fibrin glue and bone chips. Brain-stem auditory potentials were recorded at intervals up to 3 months after operation. Residual hearing could be recorded in 50% of rabbits. These animals regularly showed a 30-40 dB deterioration of hearing.     

Important factors for the hearing loss caused by the triple semicircular canal occlusion in guinea pigs.

HYPOTHESIS: Dynamic recording of the auditory brainstem response is helpful in verifying harmful procedure(s) to hearing during triple semicircular canal occlusion (TSCO) surgery. The damage to the membranous semicircular labyrinth is the single major contributor to hearing loss caused by TSCO. BACKGROUND: Posterior semicircular canal occlusion has been recognized as an efficient method of eliminating vertigo without causing a significant hearing impairment. Recently, TSCO has also been explored for its potential to treat vertigo of various causes. In limited animal studies, varied hearing impairments have been documented after TSCO. However, the major factor(s) causing hearing loss in TSCO is/are unclear. METHODS: Triple semicircular canal occlusion was performed on 36 guinea pigs in total. The cochlear function of the guinea pigs was monitored by observing the auditory brainstem response. The impact of membranous labyrinth damage on hearing was verified by a between-group comparison. RESULTS: Hearing loss during TSCO was accumulated in every step of semicircular canal manipulation. Generally, perilymph leak was found to cause a slight hearing loss that was predominately recovered during surgery. However, transaction of the membranous labyrinth usually caused a more significant hearing loss that was not recovered during the surgery. In addition, the magnitude of hearing loss seemed to be increased with the elongation of the surgery. However, the hearing can be largely recovered after the surgery even in animals with transaction of the membranous labyrinth. CONCLUSION: Hearing loss caused by TSCO can be greatly reduced by avoiding damage to the membranous labyrinth and by shortening the operation time.     

Laser irradiation of the semicircular canal: occlusion of the canal or duct

The aim of this study was to evaluate the effects of argon laser irradiation of the semicircular canals using computed tomography (CT) images and to examine the basis for laser treatment for benign paroxysmal positional vertigo (BPPV). CT images of the posterior canal were evaluated postoperatively in a patient with intractable BPPV, in whom the unilateral posterior and lateral semicircular canals were irradiated with an argon laser. In addition, bootstrap analysis of 20 patients with normal CT findings of the temporal bone was performed and previous experimentally obtained histologic findings were compared. Cross-sections of the posterior canals of 20 patients were found to show no difference in size between the right and left sides. The laser-irradiated posterior canal became narrower than that on the non-irradiated healthy side in our patient. There was a discrepancy between the CT images and experimentally obtained histologic findings that showed complete occlusion of the canal. CT images of a patient with severe vertigo demonstrated that argon laser irradiation to the blue-lined semicircular canals did not occlude the canal of the corresponding areas, while the canal of the guinea pig histologically showed complete obstruction with new bone after irradiation with the same energy (1.5 W, 0.5 s, spot size: around 200 μm in diameter). The patient has been free from vertigo for 16 years. Marked constriction of the semicircular duct corresponding to the irradiated area appeared to be effective in treating intractable BPPV.     

Selective resection of the lateral semicircular canal with hearing preservation--an animal experiment study]

The goal of our investigation was to develop a method for removing parts of the vestibular labyrinth by surgery without inducing a loss of auditory function. Three different surgical lesions were created in the lateral semicircular canal of the rabbit: (1) fenestration; (2) fibrin glue perfusion of the canal following fenestration; and (3) destruction of the semicircular canal by drilling after fenestration and fibrin glue perfusion. Brain-stem auditory potentials were recorded repeatedly up to 3 months after operation. They demonstrated preservation of hearing in all rabbits in the first group, in 78% of the second and 67% of the third group. In the last group a 20 dB deterioration of hearing was regularly noticed. Histological study revealed the utmost importance of the fibrin glue perfusion of the perilymph space of the semicircular canal inducing an interruption of the peri- and endolymph flow. A precise microsurgical technique was crucial for hearing preservation.