改良Miccoli模式内镜手术的工作腔室：WSM-I型建腔器成腔的力学特征研究

Working space establishment with Miccoli＇s approach： characteristics of the lifting force produced by a working space marker in the process of its cavity-forming

目的了解建腔器成腔力学变化特征。方法对接受改良Miccoli模式内镜甲状腺一侧腺叶及峡部切除22例，腺叶部分切除15例，行人路制备完成后，统一采用WSM-I型建腔器建腔。首次成腔后拆下提吊钩，换装上牵张力测定器，间插性地行模拟成腔实验：以0．5cm间距间断提升吊钩，同时测量钩端各高度位置时的肌皮组织牵张力。结果①牵张力的总体变化在0—27．5N。②当提升吊钩钩端至基础提吊位（Pe，腔室中心高度=1．5cm）时，对应的牵张力值为（11．2±3．5）N；继续提升吊钩钩端至极限提吊位（Pmax，19／37例的平均腔室中心高度为1．75cm，另18例为2．0cm）时，对应牵张力值为（17．5±4．3）N（腔室中心高度不同，但两组对应的力值相近）。③伴随成腔过程牵张力呈两阶段变化：当提吊钩钩端从初始位上提至Pe时，牵张力呈均匀的线性增长；当钩端继续上升至Pmax时，牵张力转呈类指数式的快速增长。最大力值出现在后一阶段。④切口长度对牵张力变化无明显影响，但肌皮组织厚度与牵张力大小呈正相关（P〈0．01）。结论①建腔器成腔时牵张力不大，其成腔近极限时的最大力值〈30N，远低于皮肤伸展术实施时所产生的力值。②整个成腔过程中力的增加呈二阶段变化，后一阶段增加明显。与之对应，肌皮组织逐步接近其粘弹性和延展性极限，而腔室空间高度也趋于最大值。③鉴于此时的成腔已近极限，再提升吊钩亦徒劳无益，而牵张力还将继续大幅增加。故此，极限提吊位所对应的牵张力值可能是成腔时整体力变化过程中的一个“拐点”。④实际成腔时的牵张力应≤Pmax的对应力值。此时不仅实现了有效成腔和最大化成腔，且可避免因不必要牵张所带来的肌皮组织损伤。

Objective To comprehend the change of the characteristics of lifting force produced by a working space marker in process of its cavity-forming. Methods 37 patients were successively operated with the surgical mode of minimally invasive video-assisted thyroidectomy （22/37 cases received a lobotomy and others underwent a partial thyroidectomy） from January to August, 2010. Instead of hand-retraction, a mechanical armworking space marker type I （ WSM-I, MIEO Medinstr Co. Ltd, China） was applied to establish a working space. After pathway making, an interlayer-cavity above the lobe was created by the space maker and endoscopic view was properly built. Following all these steps, a simulated space making procedure was performed in a way of stepwise hook-lifting （5 mm rising per time）. The lifting force （LF）was measured during the process with a modified force-measure device （FB-50, DESIK company, Germen）. Then recorded data were assessed and analyzed statistically. Results （1）Ascending scope of LF in the process of entire space-forming was 0-27.5 Newton （N）. （2）Along with hook rising, LF ascended correspondingly and 2 specific values emerged： One was 11.2 ± 3.5 N, as the lifting height approached 1.5 cm （ also a approximate position of essential space-forming （ Pc）, at which the musculo-cutaneous tissue just became tight） ; the other was 17.5 ±4.3 N , as the lifting height approached 1.75 cm （ also a approximate position of maximal space-forming （Pmax）, at which the musculo-cutaneous tissue appeared real tight, but not in a status of extreme tightness）. （3）Two types of LF ascending were found when the values transferred to a curve diagram： a palliative linearity increasing while lifting height varied from 0 to 1.5 cm （P0 to Pc） and a rapid exponent-like increasing while lifting height varied from 1.5 to 1.75cm （Pe to Pmax）. （4） Dependability analyses yielded a diverse statistical outcome： negative significance of the comparison between incision length and LF value （ P 〉 0. 05 ） , and positive significance of the comparison between skin thickness and LF value （P 〈 0.01 ）. Conclusions （1）LF produced by WSM-I while establishing a working space is proper and relatively small, since the maximal value is merely 27.5N, far less than the stress produced by ordinary cosmetic skin expansion. （2）The whole space-forming process can be divided into 2 stages according to the characteristic of LF ascending which correspond also separately to the ＂essential cavity-forming＂ and ＂the maximum cavity-forming＂ in the real establishing of a working space. （3）Attention should be paid to the later stage since in which a rapid LF increasing occurs while the appearance of musculo-cutaneous tissue changes from ＂just become tight＂ to ＂real appear tight＂. （4）LF control, especially the fine readjustment at or about Pmax should be of necessity in individual space-forming, and then, ideal working space establishment can be archived at a precisely balanced LF point： maximum cavity volume acquired and minimal tissue expansion stress produced.