猫腹侧鼓泡截骨术的术后形态学特征

王帆

Morphological aspects of tympanic bulla after ventral osteotomy in cats

猫腹侧鼓泡截骨术的术后形态学特征

Adelina Maria da SilvaI , Wilson Machado de SouzaII, Roberto Gameiro de CarvalhoIII, Gisele Fabrino MachadoI , Silvia Helena Venturoli Perri

 

翻译：王帆

 

ABSTRACT

摘要

Purpose: To evaluate tympanic bulla healing after experimental ventral osteotomy in cats. Methods: Twenty adult cats were submitted to unilateral ventral bulla osteotomy and divided into two groups: cats of A1 group (n=10) were euthanized at 8 weeks and cats of A2 group (n=10), at 16 weeks postoperative. Results: Signs of Horner’s syndrome or damage to the inner ear were not found. Open-mouth radiographs taken in the immediate postoperative showed interruption in the contour of the larger compartment of the operated bulla. The result of Mcnemar’test was significant in A2 group (*p=0.0156). Macroscopic exams revealed that the operated bullae were similar to the normal ones, with preservation of the tympanic cavity. Connective tissue at the osteotomy site of the larger compartment was significantly found in the operated bullae in both groups (McNemar test: A1 p=0.0020*; A2 p=0.0078*). Histomorphometric analyses showed that the connective tissue length at the osteotomy site was shorter in A2 group than in the A1 group (Mann-Whitney test: p=0.0021*). Conclusions: Experimental ventral osteotomy did not alter significantly the tympanic bulla conformation and complete regeneration of tympanic bulla frequently did not occur before 16 weeks of postoperative period. Key words: Ear, Middle. Otitis Media. Cats.

目的:探讨实验性猫腹侧鼓泡截骨术的鼓泡愈合情况。方法:20只成年猫行单侧腹侧鼓泡截骨术，分为两组:A1组(n=10)于术后8周实施安乐死，A2组(n=10)于术后16周实施安乐死。结果:未发现霍纳氏综合征症状或内耳损伤。术后立即拍摄的开口位x线片显示手术后鼓泡轮廓中断。A2组Mcnemar检验结果有显著性差异(*p=0.0156)。肉眼检查显示手术后鼓泡与正常鼓泡相似，但鼓室保留完好。两组手术鼓泡中均可见截骨处较大空间结缔组织(McNemar检验:A1 p=0.0020*;A2 p = 0.0078 )。组织形态定量分析显示，A2组截骨部位结缔组织长度短于A1组(Mann-Whitney检验:p=0.0021)。结论:实验性腹侧鼓泡截骨术对鼓泡形态无明显改变，术后16周内鼓泡未见完全再生。

关键词:耳部、中耳炎、猫

 

Introduction

介绍

Otitis media and polyps are the most common diseases of the middle ear in cats, and their surgical treatment usually consists of ventral tympanic bulla osteotomy. The bulla of the cat differs from that of the dog. It has a septum within the bulla which divides it into two compartments (dorsolateral and ventromedial). These compartments communicate through a fissure on the caudomedial aspect of the smaller compartment, where the septum is incomplete. When the bulla osteotomy is performed, part of this septum must be removed in order to achieve through curettage and adequate drainage of both compartments, without inflicting injury to the structures of hearing and balance or the nerve tracts which cross the middle ear.

中耳炎和息肉是猫中耳最常见的疾病，其手术治疗通常包括腹侧鼓泡截骨术。猫的鼓泡与犬的鼓泡不同。猫鼓泡中有一个鼓室中隔，将它分成两个室(背外侧和腹内侧)。这些鼓室通过较小的鼓室中隔尾部的裂缝连通，鼓室中隔在那里是不完整的。当施行鼓泡截骨术时，必须切除部分鼓室中隔，以便通过刮除和充分引流两个鼓室，而不会对听力结构和平衡或穿过中耳的神经束造成损伤。

 

Increased understanding of the response to ventral osteotomy may help the surgeon to better manage recurrences, reoperations and changes in the middle ear function. The anatomic changes that occur with healing of ventral tympanic bulla osteotomy have been studied in dogs, whose bulla consists of a single compartment. Although the crescent clinical application, we did not find experimental studies about this surgery in cats. Therefore, in this study, our objective was to evaluate the morphology of the tympanic bulla after experimental ventral osteotomy in cats by radiographic, macroscopic, histolopathological and histomorphometric exams. Risks of nerve and inner ear damage were also assessed.

增加对腹侧截骨术了解，可以帮助外科医生更好地处理复发、再手术和中耳功能的改变。在犬中研究了腹侧鼓泡截骨术愈合后的解剖变化，其鼓泡由一个单独的腔室组成。虽然临床应用再发展，但我们没有发现关于这个手术在猫的实验研究。因此，在本研究中，我们的目的是通过x线、肉眼观察、组织病理学和组织形态定量来评价实验性猫腹侧鼓泡截骨术后鼓泡的形态。也评估了神经和内耳损伤的风险。

 

Methods

方法

This study was approved by the Ethics Committee for Animal Research of the São Paulo State University – campus Araçatuba.

这项研究是由动物研究伦理委员会批准的São保罗州立大学-校园Araçatuba。

 

Animals and experimental design

试验动物与实验设计

Twenty healthy young adult (aging between 9 and 24 months) mixed breed cats (weighing 3,2 ± 0,35kg) were utilized. Ten spayed females and 10 neutered males were used. Experimental ventral tympanic bulla osteotomy (Figure 1) was performed at random in either the right or left ear. Animals were divided into two groups, according to the postoperative observation time: cats of A1 group (n=10) were euthanized at 8 weeks and cats of A2 group (n=10), at 16 weeks postoperative.

试验选用20只健康的杂交幼猫(9-24月龄)，体重为3.2±0.35kg。使用了10只已绝育雌性和10只已去势雄性。实验性腹侧鼓泡截骨术(图1)在左耳或右耳随机进行。根据术后观察时间将动物分为两组:A1组(n=10)于术后8周实施安乐死，A2组(n=10)于术后16周实施安乐死。

 

 

FIGURE 1 - Photograph of a feline skull, showing ventral tympanic bulla osteotomy (arrow). Observe the larger compartment (l) and the smaller compartment (s)

图1 -猫头骨照片，显示腹侧鼓泡截骨术(箭头)。观察大腔室(l)和小腔室(s)

 

Surgical procedure

手术过程

Food was withheld for 12 hours prior to anesthesia. The cats were premedicated with atropine (0.05mg/kg SC) and xylazine (2mg/kg SC). Anesthesia was induced with ketamine (15mg/kg, SC), and maintained with tiopental (5mg/kg IV) and fentanil (0.0125mg/kg IM). Lactated Ringer’s solution (10ml/kg IV) was administered throughout anesthesia. Enrofloxacin and ketoprofen were administered preoperatively and for 3 days postoperatively. The ventral cranial and cervical regions were clipped, prepared, and draped under sterile technique. Cats were positioned in dorsal recumbency and a paramedian skin incision was made from the angle of the mandible to the hyoid apparatus. Then, the subcutaneous tissues and the mylohyoideus muscle were incised. The bulla was located by blunt dissection of the digastricus and hyoglossus muscles and identified by palpation. The ventral surface of the tympanic bulla was exposed with a periosteal elevator. The osteotomy was initiated with a 3mm diameter pin and enlarged with rongeurs to encompass the entire ventral tympanic bulla floor (circa 10 mm x 6 mm).

麻醉前12小时禁食。猫预先使用阿托品(0.05mg/kg SC)和赛拉嗪(2mg/kg SC)。氯胺酮(15mg/kg, SC)诱导麻醉，硫喷妥钠(5mg/kg IV)和芬太尼(0.0125mg/kg IM)维持麻醉。全程麻醉给予乳酸林格液(10ml/kg IV)。术前和术后分别给予恩诺沙星和酮洛芬治疗3天。在无菌技术下对颅腹侧和颈部区域进行剃毛、准备和覆盖。猫背卧位和从下颌骨到舌骨器的角度行正中皮肤旁切口。然后切开皮下组织和下颌舌骨肌。通过钝性剥离二腹肌和舌骨舌肌定位鼓泡，并通过触诊确定。用骨膜提升器暴露鼓泡的腹侧表面。先用直径3mm的针，然后用咬骨钳扩大开口，至能覆盖整个鼓泡腹侧底部(约10 mm x 6 mm)。

 

The septum of the bulla was also opened with a 3-mm diameter pin. The tympanic cavities of the two compartments were curetted and irrigated with 0.9% saline. A 1-cm diameter Penrose drain was placed into the middle ear, exited through a separate stab incision in the skin lateral to the surgical wound and anchored with a suture. Subcutaneous layer was closed with 4-0 poliglactin 910. Skin closure was with 4-0 nylon. The Penrose drain was removed after 3 days and skin sutures removed on day 7.

也使用直径3毫米的针打开鼓泡的鼓室中隔。两个鼓室腔室都进行刮除，用0.9%的生理盐水冲洗。将直径1厘米的Penrose引流管置入中耳，在伤口外侧皮肤上单独的刺切口取出引流管，并用缝线固定。皮下组织用4-0聚乳酸910缝合。皮肤闭合用4-0尼龙线。3天后拆除Penrose引流管，7天后拆除皮肤缝合线。

 

Postoperative observations and radiographs

术后观察及x线片

After bulla osteotomy the cats were monitored for clinical signs of Horner’s syndrome, damage to the inner ear and hypoglossal nerve paralysis.

鼓泡截骨术后监测猫的霍纳氏综合征、内耳损伤和舌下神经麻痹的临床症状。

 

Radiographs were performed immediately after surgery and at the end of the study, i.e., after 8 (A1) and 16 (A2) weeks postoperative. The oblique lateral, ventrodorsal, and open-mouth views of the tympanic bullae were taken.

手术后和研究结束时，即术后8 (A1)周和16 (A2)周后，立即进行x线片检查。分别拍摄鼓泡的斜侧位、腹背侧位和开口位。

 

Macroscopic analysis, histolopathology and histomorphometry

宏肉眼观察、组织病理学和组织形态测定学

The cats were euthanized with tiopental (45mg/ kg IV) after 8 (A1 group) and 16 weeks (A2 group) postoperative. The normal and operated tympanic bullae of each cat obtained at necropsy were fixed in 10% formalin and decalcified in an aqueous solution of 5.66 formalin 10% to 1 of nitric acid (v/v). Then, each of these bullae was divided into two segments longitudinal to the larger axis of the osteotomy. The specimens were processed routinely and thin sections were made and stained with hematoxylin-eosin for microscopic evaluation.

术后8周(A1组)和16周(A2组)用硫硫喷妥钠(45mg/ kg IV)对猫实施安乐死。尸检后取每只猫的正常和手术后的鼓泡用10%的福尔马林固定，在5.66福尔马林10%到1硝酸水溶液中脱钙(v/v)。然后，每个鼓泡沿截骨大轴纵向分成两部分。常规处理标本，制作薄片，苏木精-伊红染色，显微镜下观察。

 

For the histomorphometry, the images of sections were captured using a Leica DMLS microscope connected to a Sony Power HAD 3 CCD video camera, and transferred to an image analyzer (Leica QWIN). In this planimetric study, the connective tissue length at the osteotomy site was measured in µm. The largest value obtained from each cat was included in data analysis.

对于组织形态测量，使用连接Sony Power HAD 3 CCD摄像机的徕卡DMLS显微镜捕捉切片图像，并转移到图像分析仪(徕卡QWIN)。在这个平面测量研究中，截骨部位的结缔组织长度用µm测量。从每只猫获得的最大值被纳入数据分析。

 

Statistical analysis

统计学分析

Non-parametric tests were utilized for the data analysis, taking into consideration the nature of the variables. McNemar’s test was used to compare data between operated bullae and contralateral unoperated bullae. Mann-Whitney’s test10 was used to compare histomorphometric data between groups A1 and A2. Significance was set at p≤0.05.

考虑到变量的性质，采用非参数检验进行数据分析。采用McNemar检验比较手术鼓泡和对侧未手术鼓泡的数据。Mann-Whitney 's test10用于比较A1组和A2组间的组织形态计量学数据。p≤0.05为显著性。

 

Results

结果

None of the operated cats showed clinical signs indicative of Horner’s syndrome or damage to the inner ear. In addition, we did not observe damage to the hypoglossal nerve in any of the animals.

所有接受手术的猫都没有表现出霍纳综合征或内耳损伤的临床症状。此外，我们没有观察到任何动物的舌下神经受损。

 

The open-mouth radiographs taken immediately after surgery showed an interruption in the contour of the larger bulla compartment in 4 operated cats of the A1 group and 6 from the A2 group (Figure 2; McNemar’s test, *p=0.0156). The interruption in the contour of the smaller compartment was found in only one cat (A1 group). The open-mouth radiographs taken at the end of the study showed interruption in the contour of the bulla smaller compartment in one cat of each group (A1 and A2). These radiographs showed also flatness in the contour of the larger compartment of the operated bulla of one cat from the A1 group and two cats from A2. The oblique lateral radiographs showed interruption in the contour of the larger compartment in 3 cats from A1 group and in one cat from A2 immediately postoperative and in one cat from each group at the end of the study.

术后立即拍摄的开口位x线片显示，4只A1组的手术猫和6只A2组的鼓泡轮廓中断(图2;McNemar s检验，*p=0.0156)。只有一只猫(A1组)的小中隔轮廓出现中断。在研究结束时拍摄的开口位x光片显示，每组(A1和A2)中有一只猫的鼓泡轮廓出现中断。这些x线片还显示A1组的一只猫和A2组的两只猫的手术鼓泡区轮廓平坦。斜侧位片显示，A1组的3只猫和A2组的1只猫术后立即出现较大腔室轮廓中断，研究结束时，两组的1只猫均出现较大腔室轮廓中断。

 

 

FIGURE 2 - Radiograph in open-mouth projection of cat 10 of group A2 taken immediately postoperative. Observe the interruption in the contour of the larger compartment of the operated bulla (arrow)

图2 -术后立即拍摄的A2组10号猫开口位x线片。观察手术鼓泡大腔室轮廓的中断(箭头所示)

 

The macroscopic exam revealed that the operated tympanic bullae were similar to the normal ones, with preservation of the tympanic cavity in both A1 and A2 groups. In the A1 group, 7 operated bullae presented a slight protuberance in the inner surface of the larger compartments, and the other 3 bullae had the operated area pink in color. Also in the A1 group the orifice done in the bone septum was still open in 2 cats. In A2 cats the slight protuberance in the inner surface of the larger compartment was present in all ten tympanic bullae (Figure 3). The orifice made in the bone septum remained open in 3 cats.

肉眼检查发现，手术后鼓泡与正常鼓泡相似，A1组和A2组均保留鼓室腔。A1组7个手术鼓泡在大腔室表面有轻微突起，3个手术的鼓泡手术区呈粉红色。在A1组中，2只猫的鼓室中隔孔仍然是开着的。在A2型猫中，10只鼓泡内表面均存在较大的鼓室内表面的轻微隆起(图3)。3只猫的鼓室中隔孔保持开放。

 

 

FIGURE 3 - Macroscopic aspect of the tympanic bullae of cat 12 of group A2. The concavity of the operated bulla (o) is similar to the normal one (n). Observe the light protuberance in the inner surface of the larger compartment (arrow)

图3 - A2组12只猫的鼓泡眼观表现。手术的鼓泡凹度(o)与正常鼓泡的凹度(n)相似。观察大腔室内表面的轻微突起(箭头)。

 

Connective tissue was detected in 9 and 7 operated bullae, from A1 and A2 groups, respectively. The result of McNEMAR’s test was significant for both groups A1 (P=0.0020*) and A2 (P=0.0078*). The osteotomy site was filled with connective tissue in most of the histological sections of the operated tympanic bullae of the A1 group, and areas of bone inside this connective tissue were observed in the sections of 7 cats. Thickening of the osseous wall due to lamellae deposition on both inner and outer surfaces of the larger compartment occurred mainly at the edges of the osteotomy site. Osteoblasts were common in these ossification areas. Thickening of the inner septum by lamellae deposition was also observed. Histological analysis revealed that the smaller compartment was lined with ciliated pseudostratified columnar epithelium with numerous goblet cells. The results found from histological examination of the operated tympanic bullae of A2 cats (Figure 4) were similar to those found for A1 cats. However, the osseous thickening of the larger compartment was more prominent in some animals. Complete regeneration of the larger compartment and the osteotomy site filled with woven bone was found in one bulla from A1 group and 3 bullae from A2 group. The length of connective tissue at the osteotomy site (µm) was shorter in the A2 group than in A1 (Mann-Whitney’s test, P=0.0021*; Table 1).

A1组9例，A2组7例，分别检测到结缔组织。McNEMAR检验结果在A1组(P=0.0020*)和A2组(P=0.0078*)中均有显著性差异。A1组手术的鼓泡的大部分组织学切片中截骨部位充满结缔组织，在7只猫的切片中观察到结缔组织内的骨区域。骨壁增厚主要发生在截骨部位的边缘，这是由于大腔室内外表面的板层沉积所致。成骨细胞在这些骨化区很常见。还观察到内中隔沉积增厚。组织学分析显示，小腔室内排列有含大量杯状细胞的纤毛假复层柱状上皮。A2猫手术后鼓泡的组织学检查结果(图4)与A1猫相似。然而，在一些动物中，大腔室骨增厚更为明显。A1组1个鼓泡和A2组3个鼓泡大室完全再生，截骨部位充满非层板骨。A2组截骨部位结缔组织长度(m)短于A1组(Mann-Whitney s检验，P=0.0021*;表1)。

 

 

FIGURE 4 - Photomicrograph of the operated tympanic bulla of cat 8 of group A2. Bone tissue (★) and connective tissue (*) are present at the osteotomy site, indicating intramembranous ossification. (HE, 200x)

图4 - A2组8只猫手术后鼓泡显微照片。截骨部位可见骨组织(★)和结缔组织(*)，提示膜内骨化。(他200 x)

 

Discussion

讨论

Retrospective clinical reports have indicated a high prevalence of Horner’s syndrome after ventral bulla osteotomy (about 58 to 95%). Horner’s syndrome, classically presenting with miosis, prolapse of the third eyelid and ptosis of the eyelid, results from direct damage to the postganglionic sympathetic fibers coursing to the eyes and eyelids where they pass through the tympanic cavity. No operated cats of our study showed clinical signs of Horner’s syndrome, possibly because during surgery the inner septum was carefully perforated but not removed.

回顾性临床报告表明，腹侧鼓泡截骨术后霍纳氏综合征的发病率很高(约58 - 95%)。霍纳氏综合征的典型表现为瞳孔缩小、第三眼睑脱垂和眼睑下垂，其原因是神经节后交感神经纤维通过鼓室进入眼睛和眼睑，受到直接损伤。在我们的研究中，没有一只接受手术的猫表现出霍纳综合征的临床症状，可能是因为在手术过程中，内侧鼓室中隔被小心地穿孔，但没有被移除。

 

Clinical signs (nystagmus, ataxia and head tilt) indicative of damage to the inner ear structures were not observed in any of the 20 cats studied, probably because curettage of the promontory was avoided. Similarly, only one animal showed this complication in one report series in which 23 cats with nasopharyngeal polyps and otits media were treated with ventral tympanic bulla osteotomy and polyp traction. A contrasting result was reported by Faulkner and Budsberg , who found 5 out of 12 cats submitted to ventral osteotomy showing clinical signs of damage to the inner ear. However, in this later study the cats had otitis media and externa and the polyp was present in the external ear canal. Another report5 showed a low incidence of damage to the inner ear (2 of 19 cats followed up in the postoperative). An important feature observed in this report5 was that otitis interna was evidenced in 8 of 19 cats with middle ear disease (otitis media, polyp or neoplasia) before surgery.

在20只被研究的猫中，没有观察到表明内耳结构受损的临床症状(眼球震颤、共济失调和头倾斜)，这可能是因为没有刮除隆突。类似地，在一个系列报告中，只有一只动物出现了这种并发症，其中23只患有鼻咽息肉和中耳炎的猫接受了腹侧鼓泡截骨术和息肉牵引治疗。福克纳和巴德斯伯格报告了一个对比结果，他们发现12只接受腹侧截骨手术的猫中有5只表现出内耳受损的临床症状。然而，在后来的研究中，猫患有中耳炎和外耳道息肉。另一份报告显示内耳损伤的发生率很低(19只猫中有2只在术后进行了随访)。本报告观察到的一个重要特征是，在19只患有中耳疾病(中耳炎、息肉或肿瘤)的猫中，有8只在手术前出现了中耳炎。

 

In the present study, the hypoglossal nerve was easily identified coursing along the lateral surface of the hypoglossal muscle. Although this nerve was stretched during dissection and soft-tissue retraction, tongue paralysis did not occur in any case. This same result has been previously reported.

在本研究中，舌下神经很容易被识别沿着舌下肌的外侧表面走行。尽管这条神经在剥离和软组织收缩时被拉伸，但在任何病例中都没有发生舌麻痹。同样的结果以前也报道过。

 

No abnormalities were found in the ventrodorsal radiographs of operated and normal bullae in the immediate postoperative period and at the end of the study of each group (A1 and A2). This abnormalities were probably masked by the overlap of cranial bones as described in a previous report on dogs submitted to experimental unilateral ventral osteotomy. On the other hand, open-mouth and oblique lateral radiographs afforded better visualization of the tympanic bulla, detached from the other cranial bones. This allowed detection of some features, but only in some of the oblique lateral radiographs. This is inconsistent with a previous experimental study in dogs, in which the interruption in the contour of the tympanic bulla was seen more frequently on radiographs done in oblique lateral view. But the adequacy of the radiographic plane may be related to bulla anatomy, and since the tympanic bulla of the cat seems shallower than that of the dog, the open mouth radiography may better reveal its features. The open-mouth radiographs taken immediately after surgery showed an interruption in the contour of the larger bulla compartment in 4 operated cats of A1 group and 6 of the A2 group (Figure 2). Flatness or interruption in the contour of this same compartment was observed only in some radiographs taken at the end of the study. Similar results were found in dogs submitted to experimental ventral osteotomy. Bulla radiography is often useful in evaluating middle-ear diseases. Radiographic evidences of bulla diseases include densities in the tympanic cavity and thickening of the bulla wall. In the present study, increased density of the tympanic cavity was not found in any radiograph performed 8 (A1 group) or 16 (A2 group) weeks after ventral osteotomy, indicating that the operated bulla remained filled with air and did not contain tissues or secretions. Thickening of the wall of the bulla was not observed either. Previous reports in dogs found similar results.

术后即刻和各组研究结束时，手术侧和正常侧鼓泡的腹背x线片均未发现异常(A1和A2)。这种异常可能被颅骨的重叠所掩盖，正如之前的一份报告中所描述的，犬提交了实验性的单侧腹侧截骨。另一方面，开口位和斜侧位可以更好避开其他颅骨使鼓泡显影。能检查到一些特征，但仅在一些斜侧位片可见。这与之前在犬上进行的实验研究不一致，在该研究中，在斜侧位x线片上，鼓泡轮廓中断更为常见。但x线平片的充分性可能与鼓泡解剖有关，由于猫的鼓泡似乎比犬的要浅，开口位x线片可以更好地揭示其特征。术后立即拍摄开口位影像，A1组手术的4只猫和A2组手术的6只猫显示鼓泡轮廓中断(图2)。只有在研究结束时拍摄的一些x光片中，才观察到同一腔室的轮廓平坦或中断。在接受实验性腹侧截骨的犬上也发现了类似的结果。鼓泡造影术常用于评估中耳疾病。鼓泡疾病的影像学证据包括鼓室密度和鼓泡壁增厚。本研究中，腹侧截骨术后8周(A1组)和16周(A2组)的x线片均未见鼓室密度增加，说明手术侧鼓泡仍充满空气，不含组织或分泌物。鼓泡壁增厚也未观察到。之前关于犬的报告也发现了类似的结果。

 

The macroscopic exams revealed that the concavity of the operated bullae were similar to the normal ones, with preservation of the tympanic cavity. Just a slight protuberance in the inner surface of the larger compartment was detected in most of the operated bullae (Figure 3). This disagrees with the results of a previous experimental study in dogs, in which the entire ventral tympanic bulla floor was removed.7 These authors observed that partial or complete obliteration of the tympanic cavity occurred in most of the dogs, and detected reduced auditory sensitivity in one of them (evaluated by brain stem auditory evoked potentials) probably because the bone proliferation impinged on the auditory ossicles or vestibular window. In another experimental study in dogs, the bulla osteotomy was restricted to a small area of the ventral floor and the normal volume of the tympanic cavity was almost preserved. In our study with cats, the osteotomy of the larger compartment had to be wider to give access to the inner septum. But because lateral walls were preserved, bone proliferation was slight and did not obliterate the tympanic cavity. The bone septum orifice was closed in most of the tympanic bullae of both A1 and A2 groups. However, the communication between the two compartments of the middle ear, naturally present in the caudomedial aspect of the smaller compartment, near the coclear window, was not affected by the osseous proliferation because this occurred only at the osteotomy site in both groups.

肉眼检查显示，手术鼓泡的凹性与正常鼓泡相似，鼓室腔保留完好。在大多数手术的鼓泡中，只在鼓泡的内表面发现一个轻微的突起(图3)。这与之前在犬上的实验研究结果不一致，在实验中，整个腹侧鼓泡底板被切除这些作者观察到大多数犬的鼓室部分或完全闭塞，并检测到其中一只犬的听觉敏感性降低(通过脑干听觉诱发电位评估)，这可能是因为骨增生影响了听小骨或前庭窗。在另一项犬的实验研究中，鼓泡截骨局限在腹底的一小块区域内，鼓室的正常体积几乎被保留下来。在我们对猫的研究中，截骨较大的鼓室中隔必须更宽，以便进入内隔。但由于侧壁保留，骨增生轻微，并没有使鼓室消失。A1组和A2组大部分鼓泡鼓室中隔孔闭合。然而，中耳两个腔室之间的连通，当然从小腔室尾中部的靠近耳蜗窗连通，不受骨增生的影响，因为骨增生只发生在两组的截骨部位。

 

The histological exams revealed that complete postoperative regeneration of the tympanic bulla did not occur frequently before 16 weeks, but connective tissue was present in most of the operated bullae of groups A1 and A2. The rate of regeneration was quite variable among the operated cats. High cellular loose connective tissue was detected at the osteotomy site in earlier stages. Foci of woven bone in the connective tissue were present in many sections, indicating regeneration of the tympanic bulla by intramembranous ossification. Bony proliferation was observed only in more advanced stages. The osteotomy site was filled with woven bone in the cats that presented complete regeneration of the tympanic bulla. These results are compatible with previous reports in dogs. Despite the variability, the connective tissue length at the osteotomy site, measured by histomorphometry, was shorter in the A2 group than in the A1 group (Table 1). These results showed a significant trend for complete regeneration. As a concluding remark, ventral osteotomy does not alter significantly the tympanic bulla conformation and complete regeneration of tympanic bulla usually requires more than 16 weeks from the postoperative period.

组织学检查显示，术后16周前鼓泡完全再生的情况并不常见，但A1组和A2组的大部分手术鼓泡中存在结缔组织。在接受手术的猫中，再生率变化很大。早期截骨部位发现高细胞疏松结缔组织。结缔组织的编织骨在许多切片上都有，表明鼓膜内骨化再生的鼓泡。骨增生仅在晚期才可见。在猫的截骨部位填充了非层板骨，表现出鼓泡的完全再生。这些结果与之前关于犬的报道一致。尽管存在差异，但截骨部位的结缔组织长度(通过组织形态测量法测量)在A2组比A1组短(表1)。这些结果显示了完全再生的显著趋势。综上所述，腹侧截骨不会显著改变鼓泡形态，鼓泡的完全再生通常需要术后16周以上的时间。

 

 

 

TABLE 1 – Connective tissue length in µm at the osteotomy site of bullae of group A1 (8 weeks of postoperative) and group A2 (16 weeks of postoperative) measured by the histomorphometry

表1 -用组织形态学测定法测定A1组(术后8周)和A2组(术后16周)鼓泡截骨部位结缔组织µm长度

 

 

南海

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曾医生

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