静脉桥接修复喉返神经缺损的实验研究

Experimental study of autogenous vein graft connector repairing laryngeal nerve defect in dogs

目的 探讨自体静脉桥接修复喉返神经缺损的可行性。方法 将 2 0只杂种健康成犬 ,随机分成实验 1组 (n =6 ) ,2组 (n =6 ) ,3组 (n =5 )及对照组 (n =3)。实验 1,2 ,3组分别造成受试犬左侧喉返神经缺损 1cm ,2cm ,3cm ,用各自大隐静脉进行桥接修复 ,对照组未用自体静脉修复。术后 6个月分别观察实验犬声音变化及声带活动情况 ,并行喉肌诱发动作电位和形态学检查。结果 实验 1组受试犬 6个月后发音均恢复正常 ,术侧声带无萎缩 ,与健侧基本对称 ,发音时内收明显 ,甲杓肌、环杓后肌均能引起诱发动作电位 ,光镜、电镜证实静脉移植体及神经远段有神经再生 ;实验 2 ,3组及对照组 ,受试犬术后 6个月声嘶有所改善 ,术侧声带明显萎缩 ,并固定于旁正中位 ,声门闭合裂隙大 ,健侧声带跨越中线代偿 ,甲杓肌、环杓后肌未能引出诱发动作电位 ,光镜、电镜检查示静脉移植体及神经远段未发现再生神经纤维。

Objective To investigate the feasibility of autogenous vein graft as a connector to repair recurrent laryngeal nerve(RLN) defect. Methods 20 healthy dogs were randomly devided into 4 groups: group 1(n=6), 2(n=6), 3(n=5) and control group(n=3). Left RLN of dogs in group 1,2,3 were resected for 1,2,3 centimetres respectively and followed by repairment with autogenous vein graft, while RLNS of dogs in control group were resected but not conducted by autogenous vein graft. Six months after operation, the vocal fold movement, phonation and induced action potensial as well as morphologic observation of the aryngeal muslces were studied. Results In group 1, phonation of dogs was all restored to normal. The vocal fold of RLN resected side showed no atrophy symmetrical to the normal side and adducted apparently when phonating. Furthermore thyroarythenoid muscle and posterior cricoarytenoid muscle both could generate induced action potentially. Regenerated nerves in verin graft and distal nerve were observed by light microscope and electron microscope. In group 2,3 and control group hoarseness improved six months after op eration, the vocal fold of RLN resected side was atrophied apparently and fixed paramedianly. Fissure existed in glottis when vocal fold closed, and compensative movement of opposite vocal fold across over the median line was found. Thyoarthenoid muscle and posterior cricoarytenoid muscle unable to generate an action was found. Regenerated nerves were not observed in vein graft or distal nerve by light microscope and electron microscope. Conclusions It is feasible to repair RLN defect in certain length by autogenous vein graft.