Working space establishment with Miccoli's approach: characteristics of the lifting force produced by a working space marker ln the proesss of its cavity-forming / 中华内分泌外科杂志

ABSTRACT

ObjectiveTo comprehend the change of the characteristics of lifting force produced by a working space marker in process of its cavity-forming. Methods37 patients were successively operated with the surgical mode of minimally invasive video-assisted thyroidectomy (22/37 cases received a lobotomy and others un derwent 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 modflied force-measure device (FB-50, DESIK company, Germen). Then recorded data were assessed and analyzed statistically. Results①Ascending scope of LF in the process of entire space-forming was 0-27.5 Newton (N).②Along 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 ( Pe), at which themusculo-cutaneoustissuejustbecame 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). ③Two 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 (PO to Pe) 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 ). Conclusions①LF 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. ②The 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. ③Attention 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”. ④LF 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 pre cisely balanced LF point maximum cavity volume acquired and minimal tissue expansion stress produced.