本帖最后由 王帆 于 2021-5-8 21:37 编辑
When and how to do a myringotomy – a practical guide 鼓膜切开术的时机和方法-临床实践指南
作者：Lynette Cole and Tim Nuttall 翻译：王帆
Myringotomy 鼓膜切开术 A myringotomy is a surgical incision made in the TM to allow entry into the middle ear. It is used to confirm the presence of fluid and/or debris in the middle ear, remove exudates from the middle ear cavity, obtain samples for cytological evaluation and microbial culture, drain the middle ear and to instill topical otic therapy into the middle ear cavity. 鼓膜切开术是在TM上做手术切口以便进入中耳。它用于确认中耳内是否存在液体和/或耳垢碎片，清除中耳腔中分泌物，获取样本进行细胞学检查和微生物培养，冲洗中耳，并向中耳腔内灌入外部治疗耳药。
Indications for a myringotomy 鼓膜切开术适应症 A myringotomy should be considered when one or more of the following are present: • Clinical signs consistent with otitis media or otitis interna (including acute onset peripheral vestibular disease, hearing loss, facial paralysis and/or Horner’s syndrome) with either an abnormal otoscopic appearance of the TM or abnormal middle ear findings on diagnostic imaging; OR • Abnormal otoscopic appearance of the TM (see above and Figure 1); AND/OR • Abnormal middle ear findings on diagnostic imaging (see above and Figure 3). 如果有以下一种或多种情况，应考虑鼓膜切开术:
•临床症状符合中耳炎或内耳炎(包括急性发作的外周前庭疾病、听力缺失、面神经麻痹和/或霍纳氏综合征)，伴有无论是检耳镜检查发现TM异常，还是影像学检查发现中耳异常;或
•检耳镜检查发现TM异常(见上图和图1);和/或
•影像学检查发现中耳异常(见上图及图3)。
Patient preparation, room set-up and complications 患病动物准备、设备准备和并发症 Oral and/or topical glucocorticoids should be used for two to three weeks initially to open up hyperplastic and/or stenotic ear canals, except in circumstances where the systemic use of glucocorticoids is contraindicated. A myringotomy requires general anaesthesia and involves associated risks. Patients should be stabilized before the procedures, taking into account any concomitant conditions. The patient must be intubated with a secure endotracheal tube to prevent fluid aspiration from auditory (Eustachian) tube drainage. 最初2 - 3周应口服和/或外用糖皮质激素，使增生和/或狭窄的耳道开放，除非存在全身性糖皮质激素禁忌症。鼓膜切开术需要全身麻醉，麻醉有一定风险。综合评估并发的疾病，应该手术前稳定病患体况。患者必须使用安全的气管插管，防止咽鼓管流出的液体引起误吸。
In a room set up with the video otoscope and anaesthetic ear flush (Figure 4), patients should be placed in lateral recumbency on a medically approved heating pad with the affected ear uppermost, to completely clean and evaluate the ear. Where possible, the neck should be slightly elevated such that the head is positioned at a downward angle to facilitate drainage of fluid through the nose or mouth. This reduces the risk of fluid aspiration in the case of an inadequate seal around the endotracheal tube. Other equipment and materials are listed in Table 1. Possible complications from the myringotomy and middle ear flush include Horner’s syndrome, facial nerve paralysis, vestibular disturbances, permanent TM defects and deafness. Owners should be made aware of these when giving informed consent. Owners should be instructed to watch for these complications after the procedures and topical treatment. They should discontinue treatment and contact the clinic immediately if they occur. These complications normally resolve over two to four weeks yet may be permanent. 在配有视频耳镜的房间，进行麻醉耳道冲洗(图4)，患病动物应侧卧在医用加热垫上，患耳朝上，以完全清洁和评估耳道。在可能的情况下，颈部应略微抬高，使头部呈向下倾斜，以便于液体从鼻孔或口腔排出。这降低了气管内壁周围密封不充分的情况下液体吸入气管的风险。其他设备和材料见表1。鼓膜切开术和中耳冲洗可能发生的并发症包括：霍纳氏综合征、面神经麻痹、前庭功能障碍、永久性TM缺损和失聪。应告知宠主，并签署知情同意书，应知悉这些情况。宠主应该在手术后和使用外部治疗药后关注这些并发症。如果出现这种情况，应立即停止治疗并与诊所联系。这些并发症通常在2到4周内就会消失，但也可能是永久性的。 Figure 4. Room set-up with video otoscope for an anaesthetic ear flush. 1, Monitor; 2, light source; 3, digital capture system; 4, camera box; 5, external flushing device [VETPUMP 2 (box, glass canisters and handpiece)]; 6, camera attached to otoendoscope and light source on Mayo stand; 7, defogging agent (UltraStop); 8, medically-approved heating pad; 9, tub table (Midmark Canis Major Wet Dental/Treatment Lift Table); 10, stools (Midmark Dental Stools for the clinician and technician). 图4。房间内放置视频耳镜，麻醉进行耳道冲洗。1、显示屏;2、光源;3、数字成像系统;4、相机机盒;5、外部冲洗装置[VETPUMP 2(机盒、玻璃罐、手持装置)];6、与耳内镜和光源相连的相机架;7、防雾剂(UltraStop);8、医用加热垫;9、水池操作台(Midmark Canis Major Wet Dental/Treatment Lift table);10、托盘架(Midmark Dental stool for the clinical and technician)。
Review of pertinent anatomy 相关解剖学回顾 It is important to be familiar with the normal structures of the external and middle ear. The TM is a semitransparent membrane separating the external ear canal from the middle ear. It has two sections: the smaller upper pars flaccida and the larger lower pars tensa. The manubrium of the malleus attaches to the medial surface of the pars tensa and is visible externally as the stria mallearis (Figure 5). 重点要熟悉外耳和中耳的正常结构。TM是一层半透明的膜，将外耳道和中耳分开。它有两个部分:较小的上部松弛部和较大的下部紧张部。锤骨柄附着于紧张部的内表面，与腱部内侧表面相连，从外部可观察到锤纹(图5)。
Figure 5. Normal canine tympanic membrane (right ear). A, Pars flaccida; B, pars tensa; C, stria mallearis (top = dorsal; bottom = ventral; left = caudal; right = rostral). 图5。正常犬的鼓膜(右耳)。A：鼓膜松弛部;B：鼓膜紧张部;C：锤纹(上=背侧;下=腹侧;左=尾侧;右=吻侧)。
The middle ear consists of a mucosal-lined air-filled tympanic cavity and the three auditory ossicles (malleus,incus and stapes) (Figure 6). Rostrally, it is connected to the nasopharynx by the auditory (Eustachian) tube. The tympanic cavity consists of a small dorsal epitympanic recess, the tympanic cavity proper and the ventral cavity. The largest of the three cavities is the ventral cavity, the part within the tympanic bulla. There is a bony ridge (septum bulla) that separates the tympanic cavity proper from the ventral cavity. In cats, this almost completely separates the cavity into two compartments (dorsolateral and ventromedial) making it impossible to pass a catheter into the ventromedial compartment (Figure 3). In dogs the septum bulla is incomplete allowing access to flush the whole tympanic cavity. On the medial wall of the tympanic cavity proper opposite the TM there is a bony eminence, the promontory, which houses the cochlea. There are two small foramens on the promontory; the caudolateral round or vestibular window and the dorsolateral oval or auditory window. The latter is adjacent to the pars flaccida and is covered by a thin diaphragm attached to the footplate of the stapes (Figure 7). 中耳由内衬粘膜的充满空气的鼓室和三个听小骨(锤骨、砧骨和镫骨)组成(图6)。在吻侧，它通过耳咽管(咽鼓管)与鼻咽相连。鼓室包括背侧小的鼓室上隐窝、鼓膜腔和腹侧鼓室腔。三个腔中最大的是腹侧鼓室腔，即部分鼓疱。鼓膜腔与腹侧鼓室腔之间被骨嵴(隔疱)分开。对猫来说，隔疱几乎完全覆盖，将腔体分隔成两个腔室(背外侧和腹内侧)，使得导管无法进入腹内侧腔室(图3)。对犬来说，隔疱不完全覆盖，可以冲洗到整个鼓室。在鼓膜腔内壁正对着TM的区域有一个骨质隆突，也就是耳蜗岬，其内包着耳蜗。岬上有两个小孔，尾外侧的圆窗或前庭窗和背外侧的椭圆窗或耳蜗窗。后者靠近松弛部，被镫骨踏板上一层薄膜覆盖(图7)。 Figure 6. Anatomy of the middle and inner ear and associated structures. Arrows indicate the region where the bony (facial) canal is incomplete and the facial nerve is exposed to the middle ear cavity caudal and dorsal to the stapes. In dogs, the sympathetic nerve fibres run in the carotid canal within the petrous temporal bone; in cats they form a tympanic plexus over the cochlear promontory between the round and oval windows (see also Figure 7). 图6。中耳和内耳及其相关解剖结构。箭头所指为骨质管道（面神经管）不完整的区域，面神经在镫骨尾部和背侧暴露于中耳腔。在犬上，交感神经纤维在颞骨岩内的颈动脉管中通过;在猫上，交感神经纤维形成神经丛覆盖在耳蜗岬上方，位于圆窗和椭圆窗之间(参见图7)。 Figure 7. Normal anatomy and appearance of the canine tympanic membrane (TM) and middle ear (right ear). (a) Bony structures of the middle ear with the outline of the TM and stria mallearis superimposed (broken white lines). (b) Normal canine TM and stria mallearis (broken lines) with the middle ear structures outlined (solid white lines). The anatomy of the feline middle ear is similar except that the bulla septum divides the middle ear into dorsolateral and ventromedial compartments. In addition, the tympanic plexus of the sympathetic nerve runs over the cochlear promontory between the round and oval windows. The yellow circle highlights the myringotomy site – this avoids the important structures in the dorsal and rostral middle ear and (in dogs) affords access into the ventral tympanic bulla. (D, dorsal; V, ventral; C, caudal; R, rostral). 图7。犬鼓膜(TM)和中耳(右耳)的正常解剖和外观。(a)中耳的骨结构与TM和锤纹轮廓(白色虚线)的重叠影像。(b)正常犬的TM和锤纹(虚线)，和中耳结构轮廓(白色实线)。猫中耳的解剖结构与之相似，除了隔疱将中耳分为背外侧腔和腹内侧腔。此外，交感神经丛覆盖在耳蜗岬上，位于圆窗和椭圆窗之间。黄色圆圈突出了鼓膜切开术的部位，这避开了中耳背侧和吻侧的重要结构，(对于犬)提供了进入腹侧鼓疱的通路。(D,背侧;V,腹侧;C,尾侧;R,吻侧)。
There are several nerves associated with the middle ear. The facial nerve enters the internal acoustic meatus and travels through a bony tunnel, the facial canal, of the petrous temporal bone. In dogs, this canal is incomplete and exposed to the middle ear cavity caudal and dorsal to the stapes. An infection in the middle ear could therefore infiltrate through the connective tissue and result in facial paralysis. In cats, the facial canal is complete and does not expose the facial nerves as they pass through the middle ear. Otitis media-associated facial nerve deficits, as described for dogs, are therefore rare unless there is bony destruction involving the facial canal. An ascending infection could affect the vestibulocochlear nerve resulting in otitis interna. A facial nerve branch, the chorda tympani, exits the facial canal, passes beneath the base of the malleus medially, close to the pars flaccida, and exits the middle ear to merge with the lingual branch of cranial nerve V and innervate the rostral third of the tongue. Otitis media or traumatic/surgical rupture of the pars flaccida could therefore impair taste. Another facial nerve branch, the greater petrosal nerve, provides innervation to the lacrimal and lateral nasal glands. Damage to this nerve can result in neurogenic keratoconjunctivitis sicca (KCS) and dry nose (xeromycteria) (Figure 6). Post-ganglionic fibres of the cervical sympathetic trunk are located in the dorsomedial wall of the tympanic cavity. In dogs, these run through the petrous temporal bone associated with the internal carotid artery in the carotid canal. However, cats do not have a carotid canal and the sympathetic nerve fibres enter the tympanic cavity and form a plexus overlying the cochlear promontory. Damage to the sympathetic nerve fibres can lead to Horner’s syndrome which is more common in cats as a consequence of the superficial course of the fibres in this species (Figures 6 and 7). 中耳与多条神经相关。面神经进入内耳听觉通道，并在一个骨质通道中穿过，即颞骨岩部的面神经管。在犬上，这条通道是不完整的，在镫骨的尾侧和背侧暴露于中耳腔。因此，中耳的感染可渗透结缔组织，导致面瘫。在猫上，面神经管是完整的，当面神经穿过中耳时不会暴露。罕见犬上描述的中耳炎相关的面神经损伤，除非面神经管的骨质被破坏。上行感染可影响前庭耳蜗神经，导致内耳炎。面神经的一个分支，即鼓索，从面神经管穿出，从锤骨内侧基部下方穿过，靠近松弛部，并从中耳穿出，与V脑神经的舌神经支汇合，支配舌部吻侧三分之一区域。因此，中耳炎或外伤/手术导致松弛部破裂会影响味觉。面神经的另一个分支，即岩大神经，支配泪腺和外侧鼻腺。这条神经的损伤可导致神经性干眼症(KCS)和鼻发干(鼻干燥)(图6)。颈交感干的节后纤维位于鼓室背内侧壁。在犬上，其穿过颞骨岩与颈动脉管中颈内动脉伴行。但是，猫没有颈动脉管，交感神经纤维进入鼓室并形成神经丛覆盖在耳蜗岬上。交感神经纤维的损伤会导致霍纳氏综合征，这种症状在猫上更常见，因为猫的交感神经纤维的表面发生病变(图6和7)。
When performing a myringotomy, it is important to avoid damaging the promontory, the round and oval windows, nerves and auditory ossicles to avoid iatrogenic neurological complications. These all are necessary for the amplification and transmission of sound waves to the inner ear, vestibular function and ocular innervation. Because the promontory is located opposite the mid-dorsa aspect of the TM, the oval window on the dorsolateral aspect of the promontory, the round window on the caudolateral aspect of the promontory, and the ossicles dorsorostrally in the middle ear, the myringotomy should be performed in the caudoventral quadrant of the TM (Figure 7). The required accuracy is greatly facilitated by a good-quality video otoscope. 进行鼓膜切开术时，应避免损伤岬部、圆窗和椭圆窗、神经和听小骨，以避免医源性神经学并发症。这些都是向内耳放大和传播声波、前庭功能和眼部神经支配所必需的。因为岬部位于TM背中侧的对面，椭圆窗位于岬部背外侧，圆窗位于岬部尾外侧，以及中耳吻背侧的听小骨，所以鼓膜切开术应在鼓膜的尾腹象限进行(图7)。高质量的视频耳镜可大大提高操作的准确性。
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发表于 2021-5-8 21:53:05
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