【作者】 段晨旺；

【导师】 李森恺； 李养群； 唐勇；

【作者基本信息】 中国协和医科大学 ， 整形外科， 2009， 博士

【摘要】 第一部分A型肉毒毒素在小型猪肌皮瓣扩张中的实验研究背景:肌皮瓣的临床应用范围较广,但存在面积不足或供区缺损等问题,对肌皮瓣进行扩张,可以满足较大缺损的修复同时一期封闭供区创面,但其不足之处是扩张时间长,术后回缩影响手术效果。针对上述问题,我们提出将A型肉毒毒素辅助肌皮瓣扩张,前期实验结果表明可以缩短扩张时间,增加有效扩张面积,使肌肉萎缩,肌皮瓣变薄,我们在此研究基础上进一步将A型肉毒毒素作用于肌皮瓣扩张后产生的具体作用量化,以明确其临床应用的可行性及有效性。目的:1、明确肉毒毒素辅助肌皮瓣扩张时,对增加的肌皮瓣面积来源如净增面积、移行面积的影响。2、观察肉毒毒素作用时效内及其作用消失后,扩张肌皮瓣的即时及远期回缩情况。3、从肌皮瓣的生物力学性质变化探求肉毒毒素对肌皮瓣扩张速度、扩张面积来源施加影响的机制。4、肉毒毒素在加快肌皮瓣扩张的同时是否会对肌皮瓣血运造成影响。方法:15只中国实验用小型猪纳入本实验,一侧肋腹部皮肌注射A型肉毒毒素,另一侧注射生理盐水作对照,于两侧肋腹部皮肌下植入200ml扩张器,每四天注水一次,每次注水以扩张器囊内压达90mmHg为标准。(1)对其中7只动物进行满量扩张(注水满200ml),维持扩张两周,比较两侧注水前基础囊内压、每次注水量、注水次数、扩张面积来源、皮瓣即时及远期回缩、组织学变化,在组织切片上进行显微测量肌皮瓣各层厚度;(2)4只动物亦满量扩张,扩张完成后维持两周,取材观察生物力学指标变化;(3)4只进行100%超量(注水达300ml)扩张,维持扩张3到5周,进行红外热像监测,观察扩张肌皮瓣血运。结果:1.扩张速度:相同时间间隔下,每次注水达相同囊内压,两组每次注水量不同,实验组26.1±3.2ml,对照组15.7±2.8ml(p＜0.01);每次注水前基础囊内压不同,实验组每次均低于对照组(p＜0.01);完成额定容量扩张所需的注水次数不同,实验组平均注水7.7±1.1次,对照组平均注水13.1±1.8次(p＜0.01);整体扩张时间不同:实验组平均28±3.3天,对照组为45±4.5天(p＜0.01);2.扩张面积及来源:在实际注入液体量相同的情况下,实验组所获得的扩张囊外总面积比对照组增加51.67%(p＜0.01),其中自然生长面积两组间差异无统计学意义,扩张区净增面积实验组较对照组增加32%(p＜0.01);移行面积实验组比对照组增加20.17%(p＜0.01)。3.即时及远期回缩:实验组扩张皮瓣的长度及宽度即时回缩率均小于对照组(p＜0.01);皮瓣转移术后一周、一个月、三个月、五个月时实验组皮瓣长、宽回缩小于对照组(p＜0.01);4.组织学:组织切片显示实验组的肌层、包膜层、真皮层以及皮瓣总厚度均较对照组有明显变薄(p＜0.01),同时实验组纤维包膜中胶原纤维含量较对照组有明显降低(p＜0.01);5.生物力学指标:实验组扩张肌皮瓣的拉伸杨氏弹性模量、蠕变及应力松弛性能优于对照组,但实验组的拉伸强度较对照组略有下降。两组肌皮瓣均在平行脊柱方向上变形能力强于垂直方向,也都在平行脊柱方向上拉伸强度下降(p＜0.01):6.红外热像监测显示:在扩张过程中实验组肌皮瓣远端温度略高于对照组(p＜0.05),皮瓣转移术后5天,实验组肌皮瓣中部较对照组略高(p＜0.05),远端温度差别无统计学意义。结论:1.A型肉毒毒素可以加速肌皮瓣扩张,使扩张囊外总面积较对照组增加51.67%,扩张区净增面积增加32%,移行面积增加20.17%,目前国内外尚未见关于A型肉毒毒素影响扩张囊外面积增加来源的报道。2.A型肉毒毒素可以降低扩张肌皮瓣包膜层的胶原含量,降低其真皮层、肌层和包膜层厚度,从而有效降低肌皮瓣厚度,减少肌皮瓣的即时回缩及远期回缩,有利于头面部缺损的修复重建,其量化研究亦未见研究报道。3.首次将红外热像用于监测扩张肌皮瓣血运,结果显示A型肉毒毒素辅助肌皮瓣扩张时,进行100%超量扩张是安全的,其在加快肌皮瓣扩张的同时对肌皮瓣血运兼有改善作用。4.应用A型肉毒毒素可以有效改善扩张肌皮瓣的弹性模量、蠕变及应力松弛等生物力学特性,但皮瓣的拉伸强度降低;第二章A型肉毒毒素在肌皮瓣扩张中的临床应用研究目的:探讨A型肉毒毒素应用于临床,对肌皮瓣扩张速度产生的影响,以及其给扩张器包膜、肌肉所带来的组织学变化,观察远期临床疗效。方法:临床12例患者,实验组6例,对照组6例,实验组于扩张器植入前将肉毒毒素注射于额肌,对照组不给予应用肉毒毒素,直接行扩张器植入术,比较两组扩张器注水时间,扩张器包膜厚度及额肌的组织学改变,观察临床疗效。结果:1.实验组平均注水量259ml,对照组平均注水量250ml,组间差异无统计学意义(p＞0.05),实验组平均注水时间53天,对照组平均注水时间67天,组间差异显著(p＜0.01);2.实验组扩张器包膜较对照组变薄(p＜0.01);3.实验组额肌较对照组萎缩明显,肌纤维间距加大,细胞排列不整齐,细胞形态基本正常。结论:1.应用A型肉毒毒素可以减轻额部肌皮瓣扩张阻力,加速扩张。2.A型肉毒毒素可以降低额部扩张器包膜厚度;3.A型肉毒毒素与扩张器联合应用可以使扩张肌皮瓣变薄,有利于面颈部缺损的修复重建。更多还原

【Abstract】 Part one The Experiment Research of Application of Botulinum Toxin A in myocutaneous flap expansion in minipigsBackground:Myocutaneous flap has been widely used in nowadays,problems such as area deficient and donor defect still restrict its application.Expansion of myocutaneous flap can meet the large defect at the same time close the donor site,however,the long time of expansion and contraction causing deformity need to be improved.Application of botulinum toxin A in myocutaneous flap expansion can speed up the expansion,increase the effective area,induce muscle atrophy and make thinner of myocutaneous flap.This research went further to quantify the effect of botulinum toxin A,identify the feasibility and efficacy of clinical application.Objective:To investigate the following aspects:1.what will be the influence on the origin(eg:net increase area and recruitment area) of the expansion area when botulinum toxin A was applied on myocutaneous flap expansion.2.What the contraction condition of the expanded myocutaneous flap will be in and after the period of validity of botulinum toxin A.3.The biomectmanic character changes of myocutaneous flap which were the mechanism that affect the expansion rate and the origin of expansion area.4. Whether the botulinum toxin A will affect the blood supply of myocutaneous flap when it speeding up the expansion rate.Methods:Fifteen minipigs were included in this experiment.The botulinum toxin A was injected in cutaneous muscle of one side of flank as experimental group(E group),the saline in other side as the control group(C group).Two 200ml expanders were inserted beneath the cutaneous muscle on the bilateral flank of each pig symmertrically.The expanders were filled with saline four-days-intervals and they were inflated to the same intracapsular pressure 90mmHg each time.(1) Seven minipigs were performed full amount(200ml) of expansion and then two weeks of maintain expansion.The basic intracapsular pressure,the inflated volume of each time,the expansion period,origin of expanded areas,the contraction rate and histologic changes of myocutaneous flap were compared.Thickness of each layer in myocutaneous flap was measured in histological section.(2) Four minipigs were performed full amount expansion(200ml) and then following two weeks maintain expansion,then test pieces were taken to detect the biomechanics properties of myocutaneous flap.(3) Four minipigs were performed 100% excessive expansion(300ml) and following three to five weeks of maintain expansion. Infrared thermography was taken at different stage and the temperature of the flap were drawn to reflect the blood supply of the expanded myocutaneous flap.Results:(1) Speed of expansion:under the same time interval and reach the same intracapsular pressure,inflated volume at each time in both groups were different: 26.1±3.2ml in E group and 15.7±2.8ml in C group(p<0.01);The basic intracapsular pressure in both groups were different and pressures in E group were lower than that of C group(p<0.01);Times of inflation to achieve the full expansion(200ml) were different: 7.7±1.1 times in E group and 13.1±0.8 times in C group(p<0.01);The total expansion time was different:28±3.3 days in experimental group and 45±4.5 days in control group(p<0.01).(2) The expansion areas and their origin:The increased ratio of the total expansion area in E group was 51.67%higher than C group when the actual injection volume were the same(p<0.01),the natural growth area has no significant difference between the two groups(p>0.05);Net increase area of expansion district in E group has a 32%increment than C group(p<0.01).The recruitment area in E group has a 20.17% increment than C group,there was significant difference between the two groups(p<0.01);(3)The contraction:instant contraction rate in E group was lower than C group,not only in width but in length(p<0.01);The long-term contraction in E group was smaller than C group at one week,one month,three months and five months post flap reconstruction(p<0.01);(4)The histologic examination indicated that the cutaneous muscle,capsule,dermis and the whole myocutaneous flap became thinner in E group(p<0.01),meanwhile the content of collagen fibers in E group was lower than in C group(p<0.01);(5)The biomechanics properties in E group,such as Young’s modulus of elasticity,creep and stress relaxation were improved better for expansion when compared with C group,however the tensile strength of experimental group was lower than that of control group;The deformability in direction parallel to the spine was better than that in vertical direction in both groups and the tensile strength in both groups were decreased in parallel direction(p<0.01).(6) Infrared thermograhy revealed that temperature of distal part of myocutaneous flap in E group was higher than that of C group during the expansion period(p<0.05),five days post the reconstruction of flap,temperature of central part of flap in E group was higher(p<0.05) and the temperature of distal part has no significant difference in both groups(p>0.05).Conclusions: 1.Application of botulinum toxin A in myocutaneous flap expansion can speed up the rate of expansion.The total expansion area in E group was 51.67%higher than in C group,the net increase area was 32%higher and the recruitment area was 20.17% higher when compared with C group.No report has been published with regard to effect of botulinum toxin A on the origin of expansion area.2.Botulinum toxin A can decrease the collagen content of capsule,make thinner of dermis,cutaneous muscle and capsule,thus thining the whole myocutaneous flap in E group.It can reduce the immediate stretch-back ratio and the long-term contraction which made myocutaneous flap suitable for facial repair.No quantification report was seen up to now.3.It was the first time that infrared thermography was used to monitor blood supply of expanded myocutaneous flap.Results indicated that it was safe to perform 100% excess expansion when using botulinum toxin A in expansion of myocutaneous flap. Botulinum toxin A can improve the blood supply of expanded myocutaneous flap while it accelaterate the expansion rate.4.Botulinum toxin A can improve the Young’s modulus of elasticity,creep and stress relaxation of expanded myocutaneous flap,however the tensile strength of E group was lower when compared with C group; Part two Application of Botulinum Toxin A in Clinical researchObjective:Botulinum toxin A was applied to patients in clinical treatment.To investigate the expansion speed,the histological changes of capsule and muscle and the long-term clinical efficacy.Methords:In clinic research,6 patients were in experimental group and another 6 patients in control group.Botulinum toxin A was injected in frontal muscle before expander insertion in experimental group.Then the expansion period,the thickness of capsule,histological changes of frontal muscle and therapeutic effect were observed.Results:1.The average inflated volume was 259ml in experimental group and 250ml in control group,there was not significant difference between the two groups(p＞0.05);The average expansion period was 53±6.6 days in experimental group and was 67±5.66 days in control group,there was significant difference between two groups(p＜0.01);2.The thickness of capsule in experimental group was significant thinner than that of control group(p<0.01);3.In experimental group the frontal muscle was apparently atrophy and the distance between muscle fiber was greater than that in control group.Arrangement of fiber was not regularity and the shape of muscle fiber was normal.4.The long-term therapeutic effects were satisfied.Conclusion:1.Applicating botulinum toxin A in myocutaneous flap expansion can reduce the resistance of expansion and speed up the expansion;2.The thickness of the capsule can be decreased;3.It can make the myocutaneous flap thinner which is suitable for defects repair in face and neck.更多还原