CO2激光和Nd∶YAG激光照射豚鼠鼓膜对中耳和耳蜗结构的影响
作者：周素珍 江新 蔡昌松 蔡萍
单位：周素珍(江苏省大丰市人民医院耳鼻喉科 224100)；江新 蔡昌松 蔡萍(南通医学院附属医院耳鼻喉科)
关键词：鼓膜；中耳；耳蜗；激光
中国激光医学杂志000106摘 要：目的：探讨激光鼓膜造孔对听力的影响。方法：用不同功率密度的CO2激光或Nd∶YAG激光照射豚鼠鼓膜不同时间后，观察中耳和耳蜗结构的变化。结果：以功率密度1.53 W/mm2的CO2激光照射豚鼠鼓膜2 s，或以相同功率密度的Nd∶YAG激光照射豚鼠鼓膜10 s，可引起鼓膜穿孔，听骨链和耳蜗凝固或点状炭化，凝固和炭化处柯蒂氏器官均明显破坏或变化。激光输出功率密度愈大，损伤听骨和耳蜗所需的照射时间愈短。中耳腔内注水可避免或明显减轻CO2激光对听骨和耳蜗的损伤，但对Nd∶YAG激光无效。结论：激光鼓膜造孔应严格控制激光功率密度和照射时间，以免损伤听力。用CO2激光造孔时，中耳腔内注水可避免或减轻激光对听骨和耳蜗的损伤。
, 百拇医药
分类号：TN249；R322.9+22 文献标识码：A
文章编号：1003-9430(2000)02-0021-04
Influence of CO2 Laser and Nd∶YAG Laser Irradiation to Guinea Pig's Tympanic Membrane on the Structure of the
Middle Ear and Cochlea
ZHOU Suzhen1
(Department of Otorhinolaryngology, People's Hospital of Dafeng City, Jiangsu Province, 224100, China)
, 百拇医药
JIANG Xin, CAI Changsong, CAI Ping
(Department of Otorhinolaryngology, Affiliated Hospital of Nantong Medical College, Nantong)
ABSTRACT：Objective：To study the influence of tympanic membrane perforation caused by CO2 laser and Nd∶YAG laser on hearing.Methods：The structure of the middle ear and cochlea was examined at various intervals after CO2 laser or Nd∶YAG laser irradiation with different power densities to the guinea pig's tympanic membrane.Results：The tympanic membrane irradiated for 2 seconds with CO2 laser with a power density of 1.53 W/mm2 or 10 seconds by Nd∶YAG laser with the same power density may become perforated, coagulated or carbonized in the ear bone and cochlea. The coagulated or carbonized structure in the Cortis organ was obviously damaged. The larger the output power density of laser, the shorter the irradiation time needed to impair the ear bone and cochlea. Water injection into the middle ear cavity may avoid or obviously alleviate the impairment caused by CO2 laser but exert no effect on the impairment caused by Nd∶YAG laser.Conclusions：To avoid impairment of hearing the laser power density and irradiation time should be strictly controlled in making the hole in tympanic membrene by laser. Water injection into the middle ear cavity may prevent or reduce the impairment of ear bone and cochlea when the tympanic membrane is perforated by CO2 laser irradiation.
, 百拇医药
Key words：Tympanic membrane; Middle ear; Cochlea; Lasers▲
目前国内外已广泛应用Nd∶YAG激光或CO2激光鼓膜造孔治疗渗出性中耳炎等病变，疗效较满意。为了探讨激光造孔对听力的影响，我们进行了动物实验，观察激光造孔对豚鼠中耳和耳蜗是否造成损伤。
材料和方法
一、实验动物
听力正常、体重约500 g的英国种杂色豚鼠50只，雌雄不拘，由苏州医学院提供。
二、方法
1.在体实验 32只豚鼠腹腔注射硫贲妥钠0.15 mg/g麻醉后，剪开耳道软骨部，清晰暴露鼓膜。将CO2激光导光圈置入10只豚鼠骨性耳道，与鼓膜相距约1 mm，或将Nd∶YAG激光光纤插入14只豚鼠骨性耳道内，准接触鼓膜，两者均向上倾斜30°，以不同功率密度和不同时间照射鼓膜紧张部后下方，光斑直径均为1 mm。两组各有6只豚鼠中耳腔内注入0.2 ml生理盐水后再行激光照射。用作对照的豚鼠两组各4只。
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激光照射后立即将豚鼠断头，迅速取下颞骨，剪除听泡上方部分骨质，充分暴露中耳腔听骨链和骨性耳蜗，观察凝固或炭化等损伤情况。然后用细针将耳蜗尖端挑开小孔，取出镫骨，刺破圆窗膜，用细滴管由蜗尖小孔反复灌注Bouin液1～2 min。将骨性耳蜗连同部分颞骨浸入Bouin液中固定24 h，取出后流水冲洗3～5 min，置入5%三氯醋酸水溶液脱钙约16 h，梯度乙醇脱水后，常规将标本行石蜡包埋、切片，作HE染色，行光镜观察。或按扫描电镜耳蜗标本制作法[1]制成标本后，行扫描电镜观察。
2.离体实验 将18只豚鼠的耳蜗从颞骨听泡内取出置入玻璃皿内，用激光直接照射耳蜗，或向玻璃皿内加入生理盐水，使水面超过耳蜗2或3 mm，再用激光通过水面照射耳蜗，观察隔水照射对耳蜗的影响。CO2激光照射组10只豚鼠，Nd∶YAG激光组6只豚鼠，2只豚鼠用作对照。激光照射后观察耳蜗有无凝固或炭化损伤。
结 果
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一、肉眼观察
在体实验结果见表1、2，显示两种激光鼓膜造孔均可对耳蜗造成损伤。听骨链受到激光照射的部位也出现相同改变。离体实验结果见表3、4，隔水照射可减轻CO2激光照射对耳蜗的损伤，但不能减轻Nd∶YAG激光照射的损伤。
表1 CO2激光鼓膜造孔对豚鼠耳蜗的影响
Tab.1 Influence of CO2 laser perforation in tympanic membrane on the guinea pig's cochlea 豚鼠号
No. of
animal
功率
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Power
(W)
功率密度
Power density
(W/mm2)
耳数
Ear
numbers
中耳腔注水
Water injected into the
middle ear cavity
(ml)
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平均照射时间
Average irradiation time
(s)
肉眼观察
View with naked eye
1～3
1.2
3.2
4.0
1.53
4.07
5.09
, http://www.100md.com
2
2
2
0
0
0
2.0
1.4
1.0
鼓膜上均有一小穿孔，耳蜗上开始有一炭化点
A small perforation in the tympanic membrane, a carbonization point emerged in the cochlea
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4～10
1.2
1.53
3
0.2
60.0
鼓膜穿孔，耳蜗上无炭化点 A perforation hole in the tympanic membrane, no carbonization point in the cochlea
3.2
4.07
2
0.2
, http://www.100md.com
60.0
同上 As above
4.0
5.09
3
0.2
58.0
鼓膜穿孔，耳蜗上开始有炭化点 A perforation hole in the tympanic membrane, a carbonization point emerged in the cochlea
7.7
9.80
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0.2
7.6
同上 As above
10.7
13.62
3
0.2
7.6
同上 As above
11，12
0
0
, http://www.100md.com
4
0
0
鼓膜上均无穿孔，耳蜗均正常 No perforation in the tympanic membrane, normal cochlea
13，14
0
0
4
0.2
0
同上 As above
表2 Nd∶YAG激光鼓膜造孔对豚鼠耳蜗的影响
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Tab.2 Influence of Nd∶YAG laser perforation in tympanic membrane on the quinea-pig's cochlea 豚鼠号
No. of
animal
功率
Power
(W)
功率密度
Power density
(W/mm2)
耳数
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Ear
numbers
平均照射时间
Average irradiation time
(s)
肉眼观察
View with naked eye
27，28
1.2
1.53
4
4
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鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
10
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane, the cochlea became pale
50
鼓膜穿孔，耳蜗凝固 A perforation in the tympanic membrane, and coagulation of the cochlea
130
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
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156
鼓膜穿孔，耳蜗出现点状炭化灶 A perforation in the tympanic membrane and carbonization point in the cochlea
29，30
3.1
3.95
4
5
鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
6
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane and the cochlea became pale
, http://www.100md.com
26
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
66
鼓膜穿孔，耳蜗出现点状炭化灶 Aperforation in the tympanic membrane and carbonization point in the cochlea
31，32
6.4
8.50
4
2
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鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
3
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane and the cochlea became pale
20
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
55
鼓膜穿孔，耳蜗出现点状炭化灶 A perforation in the tympanic membrane and a carbonization point in the cochlea
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33，34
11
14.01
4
1
鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
2
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane and the cochlea became pale
10
鼓膜穿孔，耳蜗凝固 A perforation in the tympanic membrane and coagulation of the cochlea
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20
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
42
鼓膜穿孔，耳蜗出现点状炭化灶 A perforation in the tympanic membrane and carbonization point in the cochlea
35～38
0
0
8
0
, http://www.100md.com
鼓膜和耳蜗均正常 Normal tympanic membrane and cochlea
注：27～34号豚鼠中耳腔内均未注水；39～44号豚鼠中耳腔内各注入0.2 ml水后，分别以与27～34号豚鼠相同的功率密度和照射时间行鼓膜Nd∶YAG激光照射，结果与未注水相同
Note: Water is not injected into the middle ear cavity in No. 27～34 guinea pigs. After 0.2 ml water is injected into the middle ear cavity in No. 39～44 guinea pigs the tympanic membranes are irradiated by Nd∶YAG laser with same power density and irradiation time as No. 27～34 guinea pigs while the result is the same as in the guinea pig's middle ear cavity without water injection.表3 CO2激光直接照射致离体耳蜗损伤的功率密度和最低照射时间
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Tab.3 The power density and the lowest irradiation time of the cochlea impaired by direct CO2 laser irradiation 豚鼠号
Animal
numbers
功率
Power
(W)
功率密度
Power density
(W/mm2)
, http://www.100md.com
耳蜗数
Cochlea
numbers
水面至耳蜗垂直距离
The vertical distance from
water level to cochlea
(mm)
平均照射时间
Average irradiation time
(s)
肉眼观察
, http://www.100md.com
View with naked eye
15
1.2
1.53
2
0
1.2
耳蜗上开始有炭化点 A carbonization point emerged in the cochlea
16
4.0
5.09
2
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0
0.8
同上 As above
17
1.2
1.53
2
2
60.0
耳蜗上无炭化点 No carbonization point in the cochlea
18
3.2
, http://www.100md.com
4.07
2
2
60.0
同上 As above
19
4.0
5.09
2
2
56.0
耳蜗上开始有炭化点 A carbonization point emerged in the cochlea
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20
5.3
6.75
2
2
18.0
同上 As above
21
7.7
9.80
2
2
7.0
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同上 As above
22
10.7
13.62
2
2
1.5
同上 As above
23
7.7
9.80
2
3
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60.0
耳蜗上无炭化点 No carbonization point in the cochlea
24
10.7
13.62
2
3
60.0
同上 as above
25，26
0
0
, http://www.100md.com
4
0
0
耳蜗上无炭化点 No carbonization point in the cochlea
表4 Nd∶YAG激光直接照射致离体耳蜗损伤的功率密度和最低照射时间
Tab.4 The power density and the lowest irradiation time of the cochlea impaired by direct YAG laser irradiation 豚鼠号
Animal
numbers
功率
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Power
(W)
功率密度
Power density
(W/mm2)
耳蜗数
Cochlea
numbers
水面至耳蜗垂直距离
The vertical distance from
water level to cochlea
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(mm)
平均照射时间
Average irradiation time
(s)
肉眼观察
View with naked eye
45
1.2
1.53
2
3
9
, http://www.100md.com 耳蜗开始发白 The cochlea became pale
48
耳蜗凝固 Coagulation emerged in the cochlea
126
耳蜗膨胀增大 Swelling of the cochlea
152
耳蜗出现点状炭化 Carbonization point in the cochlea
46
3.1
3.95
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2
3
6
耳蜗开始发白 The cochlea became pale
27
耳蜗膨胀增大 Swelling of the cochlea
67
耳蜗出现点状炭化 Carbonization point in the cochlea
47
6.4
8.50
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2
3
3
耳蜗开始发白 The cochlea became pale
21
耳蜗膨胀增大 Swelling of the cochlea
57
耳蜗出现点状炭化 Carbonization point in the cochlea
48
11
14.01
, http://www.100md.com
2
3
2
耳蜗开始发白 The cochlea became pale
22
耳蜗膨胀增大 Swelling of in the cochlea
43
耳蜗出现点状炭化 Carbonization point in the cochlea
49，50
0
0
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4
0
0
耳蜗正常 Normal cochlea
二、光镜观察
CO2激光照射所致耳蜗炭化点处的柯蒂氏器内有炭化圈，周围细胞结构模糊不清，基底膜和内外毛细胞均有不同程度破坏和中断。中阶、鼓阶、前庭阶和柯蒂氏器细胞内有较多粗细不等的炭化块和颗粒，以炭化圈为中心向外逐步稀少。
Nd∶YAG激光照射所致耳蜗凝固或炭化灶内，见柯蒂氏器内结构模糊不清，有不同程度破坏和变形，基底膜弯曲变形或中断，内外毛细胞和支持细胞破碎变形或残缺不全；部分炭化点处的柯蒂氏器内有炭化颗粒。
三、扫描电镜观察
, http://www.100md.com
CO2激光或Nd∶YAG激光照射所致炭化处的耳蜗蜗轴骨质有明显缺损，结构均破坏、消失。讨 论
根据本组实验结果，提示临床上用激光行鼓膜造孔治疗渗出性中耳炎等病变时，应严格掌握激光剂量。以下参数可供参考：CO2激光照射鼓膜(中耳腔内无渗液)的功率密度为1.53、4.07和5.09W/mm2时，照射时间应分别限制在2.0、1.4和1.0 s以内。如中耳腔内渗液较多，或先通过鼓膜注入0.3 ml地塞米松或生理盐水，再用CO2激光照射鼓膜,则可避免听骨和耳蜗的损伤。但这种方法对Nd∶YAG激光无效。Nd∶YAG激光照射鼓膜的功率密度为1.53、3.95、8.50和14.01 W/mm2时，照射时间应分别限制在10、6、3、和2 s以内。
在实验中我们还观察到，豚鼠骨性耳蜗在中耳腔内的位置是从后下向前上倾斜，鼓膜紧张部中央距耳蜗1.5 mm，紧张部前下方中点和后下方中点距耳蜗均为2 mm。激光从前下方中点进入、向上倾科35°，正中耳蜗第1～2圈。激光由后下方中点进入、向上倾科30°，正中耳蜗第3～4圈。■
作者简介：周素珍(1952-)，女，江苏省大丰市人，大丰市人民医院耳鼻喉科主任，副主任医师，主要从事耳鼻喉科研究。
参考文献：
[1] 王之贤，曾一同. 耳蜗显微与超微结构图谱[M]. 天津：天津科学技术出版社，1988. 152-153.
收稿日期：1998-09-30, 百拇医药
单位：周素珍(江苏省大丰市人民医院耳鼻喉科 224100)；江新 蔡昌松 蔡萍(南通医学院附属医院耳鼻喉科)
关键词：鼓膜；中耳；耳蜗；激光
中国激光医学杂志000106摘 要：目的：探讨激光鼓膜造孔对听力的影响。方法：用不同功率密度的CO2激光或Nd∶YAG激光照射豚鼠鼓膜不同时间后，观察中耳和耳蜗结构的变化。结果：以功率密度1.53 W/mm2的CO2激光照射豚鼠鼓膜2 s，或以相同功率密度的Nd∶YAG激光照射豚鼠鼓膜10 s，可引起鼓膜穿孔，听骨链和耳蜗凝固或点状炭化，凝固和炭化处柯蒂氏器官均明显破坏或变化。激光输出功率密度愈大，损伤听骨和耳蜗所需的照射时间愈短。中耳腔内注水可避免或明显减轻CO2激光对听骨和耳蜗的损伤，但对Nd∶YAG激光无效。结论：激光鼓膜造孔应严格控制激光功率密度和照射时间，以免损伤听力。用CO2激光造孔时，中耳腔内注水可避免或减轻激光对听骨和耳蜗的损伤。
, 百拇医药
分类号：TN249；R322.9+22 文献标识码：A
文章编号：1003-9430(2000)02-0021-04
Influence of CO2 Laser and Nd∶YAG Laser Irradiation to Guinea Pig's Tympanic Membrane on the Structure of the
Middle Ear and Cochlea
ZHOU Suzhen1
(Department of Otorhinolaryngology, People's Hospital of Dafeng City, Jiangsu Province, 224100, China)
, 百拇医药
JIANG Xin, CAI Changsong, CAI Ping
(Department of Otorhinolaryngology, Affiliated Hospital of Nantong Medical College, Nantong)
ABSTRACT：Objective：To study the influence of tympanic membrane perforation caused by CO2 laser and Nd∶YAG laser on hearing.Methods：The structure of the middle ear and cochlea was examined at various intervals after CO2 laser or Nd∶YAG laser irradiation with different power densities to the guinea pig's tympanic membrane.Results：The tympanic membrane irradiated for 2 seconds with CO2 laser with a power density of 1.53 W/mm2 or 10 seconds by Nd∶YAG laser with the same power density may become perforated, coagulated or carbonized in the ear bone and cochlea. The coagulated or carbonized structure in the Cortis organ was obviously damaged. The larger the output power density of laser, the shorter the irradiation time needed to impair the ear bone and cochlea. Water injection into the middle ear cavity may avoid or obviously alleviate the impairment caused by CO2 laser but exert no effect on the impairment caused by Nd∶YAG laser.Conclusions：To avoid impairment of hearing the laser power density and irradiation time should be strictly controlled in making the hole in tympanic membrene by laser. Water injection into the middle ear cavity may prevent or reduce the impairment of ear bone and cochlea when the tympanic membrane is perforated by CO2 laser irradiation.
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Key words：Tympanic membrane; Middle ear; Cochlea; Lasers▲
目前国内外已广泛应用Nd∶YAG激光或CO2激光鼓膜造孔治疗渗出性中耳炎等病变，疗效较满意。为了探讨激光造孔对听力的影响，我们进行了动物实验，观察激光造孔对豚鼠中耳和耳蜗是否造成损伤。
材料和方法
一、实验动物
听力正常、体重约500 g的英国种杂色豚鼠50只，雌雄不拘，由苏州医学院提供。
二、方法
1.在体实验 32只豚鼠腹腔注射硫贲妥钠0.15 mg/g麻醉后，剪开耳道软骨部，清晰暴露鼓膜。将CO2激光导光圈置入10只豚鼠骨性耳道，与鼓膜相距约1 mm，或将Nd∶YAG激光光纤插入14只豚鼠骨性耳道内，准接触鼓膜，两者均向上倾斜30°，以不同功率密度和不同时间照射鼓膜紧张部后下方，光斑直径均为1 mm。两组各有6只豚鼠中耳腔内注入0.2 ml生理盐水后再行激光照射。用作对照的豚鼠两组各4只。
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激光照射后立即将豚鼠断头，迅速取下颞骨，剪除听泡上方部分骨质，充分暴露中耳腔听骨链和骨性耳蜗，观察凝固或炭化等损伤情况。然后用细针将耳蜗尖端挑开小孔，取出镫骨，刺破圆窗膜，用细滴管由蜗尖小孔反复灌注Bouin液1～2 min。将骨性耳蜗连同部分颞骨浸入Bouin液中固定24 h，取出后流水冲洗3～5 min，置入5%三氯醋酸水溶液脱钙约16 h，梯度乙醇脱水后，常规将标本行石蜡包埋、切片，作HE染色，行光镜观察。或按扫描电镜耳蜗标本制作法[1]制成标本后，行扫描电镜观察。
2.离体实验 将18只豚鼠的耳蜗从颞骨听泡内取出置入玻璃皿内，用激光直接照射耳蜗，或向玻璃皿内加入生理盐水，使水面超过耳蜗2或3 mm，再用激光通过水面照射耳蜗，观察隔水照射对耳蜗的影响。CO2激光照射组10只豚鼠，Nd∶YAG激光组6只豚鼠，2只豚鼠用作对照。激光照射后观察耳蜗有无凝固或炭化损伤。
结 果
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一、肉眼观察
在体实验结果见表1、2，显示两种激光鼓膜造孔均可对耳蜗造成损伤。听骨链受到激光照射的部位也出现相同改变。离体实验结果见表3、4，隔水照射可减轻CO2激光照射对耳蜗的损伤，但不能减轻Nd∶YAG激光照射的损伤。
表1 CO2激光鼓膜造孔对豚鼠耳蜗的影响
Tab.1 Influence of CO2 laser perforation in tympanic membrane on the guinea pig's cochlea 豚鼠号
No. of
animal
功率
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Power
(W)
功率密度
Power density
(W/mm2)
耳数
Ear
numbers
中耳腔注水
Water injected into the
middle ear cavity
(ml)
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平均照射时间
Average irradiation time
(s)
肉眼观察
View with naked eye
1～3
1.2
3.2
4.0
1.53
4.07
5.09
, http://www.100md.com
2
2
2
0
0
0
2.0
1.4
1.0
鼓膜上均有一小穿孔，耳蜗上开始有一炭化点
A small perforation in the tympanic membrane, a carbonization point emerged in the cochlea
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4～10
1.2
1.53
3
0.2
60.0
鼓膜穿孔，耳蜗上无炭化点 A perforation hole in the tympanic membrane, no carbonization point in the cochlea
3.2
4.07
2
0.2
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60.0
同上 As above
4.0
5.09
3
0.2
58.0
鼓膜穿孔，耳蜗上开始有炭化点 A perforation hole in the tympanic membrane, a carbonization point emerged in the cochlea
7.7
9.80
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0.2
7.6
同上 As above
10.7
13.62
3
0.2
7.6
同上 As above
11，12
0
0
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4
0
0
鼓膜上均无穿孔，耳蜗均正常 No perforation in the tympanic membrane, normal cochlea
13，14
0
0
4
0.2
0
同上 As above
表2 Nd∶YAG激光鼓膜造孔对豚鼠耳蜗的影响
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Tab.2 Influence of Nd∶YAG laser perforation in tympanic membrane on the quinea-pig's cochlea 豚鼠号
No. of
animal
功率
Power
(W)
功率密度
Power density
(W/mm2)
耳数
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Ear
numbers
平均照射时间
Average irradiation time
(s)
肉眼观察
View with naked eye
27，28
1.2
1.53
4
4
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鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
10
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane, the cochlea became pale
50
鼓膜穿孔，耳蜗凝固 A perforation in the tympanic membrane, and coagulation of the cochlea
130
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
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156
鼓膜穿孔，耳蜗出现点状炭化灶 A perforation in the tympanic membrane and carbonization point in the cochlea
29，30
3.1
3.95
4
5
鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
6
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane and the cochlea became pale
, http://www.100md.com
26
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
66
鼓膜穿孔，耳蜗出现点状炭化灶 Aperforation in the tympanic membrane and carbonization point in the cochlea
31，32
6.4
8.50
4
2
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鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
3
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane and the cochlea became pale
20
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
55
鼓膜穿孔，耳蜗出现点状炭化灶 A perforation in the tympanic membrane and a carbonization point in the cochlea
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33，34
11
14.01
4
1
鼓膜穿孔，耳蜗正常 A perforation in the tympanic membrane, normal cochlea
2
鼓膜穿孔，耳蜗开始发白 A perforation in the tympanic membrane and the cochlea became pale
10
鼓膜穿孔，耳蜗凝固 A perforation in the tympanic membrane and coagulation of the cochlea
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20
鼓膜穿孔，耳蜗膨胀增大 A perforation in the tympanic membrane and swelling of the cochlea
42
鼓膜穿孔，耳蜗出现点状炭化灶 A perforation in the tympanic membrane and carbonization point in the cochlea
35～38
0
0
8
0
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鼓膜和耳蜗均正常 Normal tympanic membrane and cochlea
注：27～34号豚鼠中耳腔内均未注水；39～44号豚鼠中耳腔内各注入0.2 ml水后，分别以与27～34号豚鼠相同的功率密度和照射时间行鼓膜Nd∶YAG激光照射，结果与未注水相同
Note: Water is not injected into the middle ear cavity in No. 27～34 guinea pigs. After 0.2 ml water is injected into the middle ear cavity in No. 39～44 guinea pigs the tympanic membranes are irradiated by Nd∶YAG laser with same power density and irradiation time as No. 27～34 guinea pigs while the result is the same as in the guinea pig's middle ear cavity without water injection.表3 CO2激光直接照射致离体耳蜗损伤的功率密度和最低照射时间
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Tab.3 The power density and the lowest irradiation time of the cochlea impaired by direct CO2 laser irradiation 豚鼠号
Animal
numbers
功率
Power
(W)
功率密度
Power density
(W/mm2)
, http://www.100md.com
耳蜗数
Cochlea
numbers
水面至耳蜗垂直距离
The vertical distance from
water level to cochlea
(mm)
平均照射时间
Average irradiation time
(s)
肉眼观察
, http://www.100md.com
View with naked eye
15
1.2
1.53
2
0
1.2
耳蜗上开始有炭化点 A carbonization point emerged in the cochlea
16
4.0
5.09
2
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0
0.8
同上 As above
17
1.2
1.53
2
2
60.0
耳蜗上无炭化点 No carbonization point in the cochlea
18
3.2
, http://www.100md.com
4.07
2
2
60.0
同上 As above
19
4.0
5.09
2
2
56.0
耳蜗上开始有炭化点 A carbonization point emerged in the cochlea
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20
5.3
6.75
2
2
18.0
同上 As above
21
7.7
9.80
2
2
7.0
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同上 As above
22
10.7
13.62
2
2
1.5
同上 As above
23
7.7
9.80
2
3
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60.0
耳蜗上无炭化点 No carbonization point in the cochlea
24
10.7
13.62
2
3
60.0
同上 as above
25，26
0
0
, http://www.100md.com
4
0
0
耳蜗上无炭化点 No carbonization point in the cochlea
表4 Nd∶YAG激光直接照射致离体耳蜗损伤的功率密度和最低照射时间
Tab.4 The power density and the lowest irradiation time of the cochlea impaired by direct YAG laser irradiation 豚鼠号
Animal
numbers
功率
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Power
(W)
功率密度
Power density
(W/mm2)
耳蜗数
Cochlea
numbers
水面至耳蜗垂直距离
The vertical distance from
water level to cochlea
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(mm)
平均照射时间
Average irradiation time
(s)
肉眼观察
View with naked eye
45
1.2
1.53
2
3
9
, http://www.100md.com 耳蜗开始发白 The cochlea became pale
48
耳蜗凝固 Coagulation emerged in the cochlea
126
耳蜗膨胀增大 Swelling of the cochlea
152
耳蜗出现点状炭化 Carbonization point in the cochlea
46
3.1
3.95
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2
3
6
耳蜗开始发白 The cochlea became pale
27
耳蜗膨胀增大 Swelling of the cochlea
67
耳蜗出现点状炭化 Carbonization point in the cochlea
47
6.4
8.50
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2
3
3
耳蜗开始发白 The cochlea became pale
21
耳蜗膨胀增大 Swelling of the cochlea
57
耳蜗出现点状炭化 Carbonization point in the cochlea
48
11
14.01
, http://www.100md.com
2
3
2
耳蜗开始发白 The cochlea became pale
22
耳蜗膨胀增大 Swelling of in the cochlea
43
耳蜗出现点状炭化 Carbonization point in the cochlea
49，50
0
0
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4
0
0
耳蜗正常 Normal cochlea
二、光镜观察
CO2激光照射所致耳蜗炭化点处的柯蒂氏器内有炭化圈，周围细胞结构模糊不清，基底膜和内外毛细胞均有不同程度破坏和中断。中阶、鼓阶、前庭阶和柯蒂氏器细胞内有较多粗细不等的炭化块和颗粒，以炭化圈为中心向外逐步稀少。
Nd∶YAG激光照射所致耳蜗凝固或炭化灶内，见柯蒂氏器内结构模糊不清，有不同程度破坏和变形，基底膜弯曲变形或中断，内外毛细胞和支持细胞破碎变形或残缺不全；部分炭化点处的柯蒂氏器内有炭化颗粒。
三、扫描电镜观察
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CO2激光或Nd∶YAG激光照射所致炭化处的耳蜗蜗轴骨质有明显缺损，结构均破坏、消失。讨 论
根据本组实验结果，提示临床上用激光行鼓膜造孔治疗渗出性中耳炎等病变时，应严格掌握激光剂量。以下参数可供参考：CO2激光照射鼓膜(中耳腔内无渗液)的功率密度为1.53、4.07和5.09W/mm2时，照射时间应分别限制在2.0、1.4和1.0 s以内。如中耳腔内渗液较多，或先通过鼓膜注入0.3 ml地塞米松或生理盐水，再用CO2激光照射鼓膜,则可避免听骨和耳蜗的损伤。但这种方法对Nd∶YAG激光无效。Nd∶YAG激光照射鼓膜的功率密度为1.53、3.95、8.50和14.01 W/mm2时，照射时间应分别限制在10、6、3、和2 s以内。
在实验中我们还观察到，豚鼠骨性耳蜗在中耳腔内的位置是从后下向前上倾斜，鼓膜紧张部中央距耳蜗1.5 mm，紧张部前下方中点和后下方中点距耳蜗均为2 mm。激光从前下方中点进入、向上倾科35°，正中耳蜗第1～2圈。激光由后下方中点进入、向上倾科30°，正中耳蜗第3～4圈。■
作者简介：周素珍(1952-)，女，江苏省大丰市人，大丰市人民医院耳鼻喉科主任，副主任医师，主要从事耳鼻喉科研究。
参考文献：
[1] 王之贤，曾一同. 耳蜗显微与超微结构图谱[M]. 天津：天津科学技术出版社，1988. 152-153.
收稿日期：1998-09-30, 百拇医药